Eu escrevi esta função para injetar DLL no processo em execução:

DLL_Results CDLL_Loader::InjectDll()
{
    DWORD ThreadTeminationStatus;
    LPVOID VirtualMem;
    HANDLE hProcess, hRemoteThread;
    HMODULE hModule;

    if (!isInit())
        return NOT_INIT;

    if (isInjected())
        return DLL_ALREADY_HOOKED;

    hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, ProcessID);
    if (hProcess == NULL)
        return PROCESS_ERROR_OPEN;

    VirtualMem = VirtualAllocEx (hProcess, NULL, strlen(DllFilePath), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
    if (VirtualMem == NULL)
        return PROCESS_ERRORR_VALLOC;

    if (WriteProcessMemory(hProcess, (LPVOID)VirtualMem, DllFilePath, strlen(DllFilePath), NULL) == 0)
    {
        VirtualFreeEx(hProcess, NULL, (size_t)strlen(DllFilePath), MEM_RESERVE|MEM_COMMIT);
        CloseHandle(hProcess); 
        return PROCESS_ERROR_WRITE;
    }

    hModule = GetModuleHandle(L"kernel32.dll");
    hRemoteThread = CreateRemoteThread(hProcess, NULL, 0, 
                        (LPTHREAD_START_ROUTINE)GetProcAddress(hModule, "LoadLibraryA"),
                          (LPVOID)VirtualMem, 0, NULL);

    if (hRemoteThread == NULL)
    {
        FreeLibrary(hModule);
        VirtualFreeEx(hProcess, NULL, (size_t)strlen(DllFilePath), MEM_RESERVE | MEM_COMMIT);
        CloseHandle(hProcess); 
        return PROCESS_ERROR_CREATE_RTHREAD;
    }

    WaitForSingleObject(hRemoteThread, INFINITE);
    GetExitCodeThread(hRemoteThread, &ThreadTeminationStatus);
    FreeLibrary(hModule);

    VirtualFreeEx(hProcess, NULL, (size_t)strlen(DllFilePath), MEM_RESERVE | MEM_COMMIT);
    CloseHandle(hRemoteThread);
    CloseHandle(hProcess); 
    injected = true;
    return DLLHOOK_OK;
}

E funciona muito bem, mas quando eu estava tentando ejetar a dll, não consegui encontrar informações sobre o desengate ... estava tentando criar alguma função para fazer isso e acho que estou perto disso é o que tenho. longe

é o caminho certo? Nesse caso, qual parâmetro devo passar na instância createRemoteThread do VirtualMem (que foi usada na função de injeção) ...

DLL_Results CDLL_Loader::EjectDll()
{
    DWORD ThreadTeminationStatus;
    HANDLE hProcess, hRemoteThread;
    HMODULE hModule;

    if (isInjected())
        return DLLEJECT_OK;

    hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, ProcessID);
    if (hProcess == NULL)
        return PROCESS_ERROR_OPEN;

    hModule = GetModuleHandle(L"kernel32.dll");
    hRemoteThread = CreateRemoteThread(hProcess, NULL, 0, 
                        (LPTHREAD_START_ROUTINE)GetProcAddress(hModule, "FreeLibrary"),
                          /*(LPVOID)VirtualMem <- What do i need to send here?*/, 0, NULL);

    if (hRemoteThread != NULL)
    {
        WaitForSingleObject(hRemoteThread, INFINITE);
        GetExitCodeThread(hRemoteThread, &ThreadTeminationStatus);
    }

    CloseHandle(hRemoteThread);
    CloseHandle(hProcess); 
    injected = false;
    return DLLEJECT_OK;
}