I am testing a malware that built as COM EXE service. This exe file had a digital signature.
I succeeded to remove the digital signature for trying to modify it for reverse engineering tests.
But when I open it in OllyDbg and make any tiny change, the malware crash and not runs at all. Even if I tries to change one byte in the code cave to
nop command, the malware not running.
Why can't I change it even in the code cave? Any idea?