[Reverse Engineering] Beating a trial on a .net crackme
Today we are dealing with yet another .net crackme. Let’s see how it goes…
The crackme is a sort of X-times usage trial. After we’ve opened the executable 10 times we have the opportunity to test if we cracked the trial or not.
Using dotPeek we can decompile the binary, search for the class that is in charge of keeping track of the trial.
Using dnSpy we can not only inspect the binary but patch the code with ease. If we change the validation being made on this line in a way it can never be true we’d effectively cracked the binary.
And so I did, changing the hardcoded 9 to a 0 makes the validation useless as it could never be true.
Now we can start the binary as many times as we want without any issues!