How to find a custom function's address to hook/detour in another running process?

Question

Related to: How to find a functions address to hook/detour in an EXE file?

I have to detour a function defined inside the executable I'm injecting my code into. The application is Open-Source so I know everything about the function I'd need for hooking it.

In the accepted answer to that question, it says to hook some low level windows api functions first to get the address of the actual function I want to hook, question is, which windows API function should I hook?

Answer 1

Choose an API inside your target EXE that get called first when it runs. Load it to OllyDbg and trace until you find one.