Cool PYC – ByteCode Crackme Challenge

Hello again!, after a long time. Today I’m going to share with you a Compiled Python File (.pyc) crackme which is avaiable in This is my first experience with pyc files in reversing because we talk about them rarely in this area.

Here is the challenge :

It suggests to retrieve the password to validate this challenge.

Let’s run ch19.pyc  ( You have to install python 3.1, if you don’t have it )


Okay, fine. Now show us your inside ch19! 😀


ord() method convert ASCII to Integer values. We can simply use chr() to reconvert them back

There is an encrypted list named SOLUCE. This list was generated by converting a string/Flag to integer values. Can we convert back these values to a string? In this situation it’s not possible because they have used XOR operator when generating integers.

So I wrote a simple decryption algorithm which bruteforces each integer in SOLUCE list and find which ASCII character is it.


Full Code :

Let’s execute 😉


He hates RUBY then! 😀 😀

Another cool thing happened when I sending the flag in the challenge. Look at bellow one.


What!! I just solved your crackme by bruteforcing, actually are you telling me that I’m stupid right now?!

Frustrated moment… Did I miss something..

Tried once again and it worked!


Site just adviced not to bruteforce the site itself when finding the password. It detected as I did because of sending wrong passwords two times.


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