Is it possible to modify a file without changing the checksum?

Question

hex

There is a program that creates a working file. If this file is changed in a hex editor (which eventually needs to be done), then the program understands this and gives an error. I assume that a checksum is written to the file and then it is checked. But I can't find where she is. Maybe there is some way to find it? Or bypass the check.

Answer 1

IDA is here to help. In principle, it is possible to change a file so that some checksum remains the same.