How to protect the game from being replaced by a hacker DLL?

Question

Unity

There is a game in the FPS genre, the Unity 3D engine. Cheating basically consists in replacing the .dll file with a cheating one. How to protect the game from being replaced by a hacker DLL?
What other APIs or software are there to protect client-server applications from interference by third-party programs?

Answer 1

I'm not a coder, but it seems to me that a simple checksum check of the application's critical files (which guarantees no changes) will give a good result.
Or use some kind of paid solution, which I think is enough.
Look for information about counter strike anti-cheats, I think this is the most advanced technology)