What coding language are CS-GO hacks written in?

Is there any specific coding language?

No, you can write it in pretty much anything.

Write a hack in Brainfuck then. I would love to see that. Or in Robot C. Or StarLogo.

Basically anything that can read and write and attach to processes

No you can use any language which can read/write memory to different processee. But I do reccommend C++ because most people write their cheats in C++ and you'll get alot more help here if you use that. It's also more sources and tutorials made in C++ for CS:GO cheating than any other language I believe.