Simple one file header for hijacking dll for desired executable to do 3rd party modifying without dll injection.
#include "xxx.hpp"
int __stdcall DllMain(HMODULE m_hModule, DWORD m_dReason, void* m_pReserved)
{
if (m_dReason == DLL_PROCESS_ATTACH)
{
sneakyevil_DllHijack::Initialize();
// Your code...
}
return 1;
}