| As noted before, the entered key is used to decrypt the routine to display the message box.
The pointer to the MessageboxA function is passed to the routine as a pointer.
- Since the description says you should get a "success" message and the string is not available in the executable, it should be part of the encrypted routine.
- The routine should return 0xc to not additionally show the "fail" messagebox.
I searched for printable keys that would resolve to the routine either contain "success" or "ccus" (stack string) without any success.
In my opinion this is just a guessing game making assumptions about the XORed code - hence a guessing game and not a proper crackme.