File Corrupted Error

[AcarX]

Hello there. Some of you may have seen this error before. "File corrupted!. This program has been manipulated and maybe it's infected by a virus or cracked. This file wont work anymore.". I am wondering which library/dll is prompting this message. In my case it occurs if I edit a specific exe(even a single bit) without actually breaking it.

[Peter87]

Why are you changing a bit in an exe file? Not sure but maybe the exe format has some kind of checksum and if you change the file the checksum will no longer be correct.

[AcarX]

I'm trying to get rid of a function call alongside with the parameters being pushed by nop'ing them. Looks like either I have to somehow modify MapFileAndCheckSum before it's being called or nop the address during runtime.