Cracking

Hello community

I’m so stuck in this challenger, because i have been scanning the ch15.exe file, and i found the hypothetical key "Gratz man :)", however, when i send it to validate the challenger, it say me "Just try again". If someone would guide me in this task i will greatful.
Thanks for your answers.

The "Gratz..." message is what you will get when you insert the correct password. The password that you need to insert to get that message is also the flag for the challenge.
Good luck!
NonStandardModel

Plz give a hint on this