Challenger

December 27, 2017 ยท View on GitHub

Challenger accellerates dictionary attacks on NETLMv1/MSCHAPv2 hashes by using a partial-bruteforce/rainbow-tablea hybrid technique. Much like traditional rainbow tables techniques, challenger has a tool (rtchallenge.py) to convert a wordlist into a rainbow table. This is not normally possibe for NETLMv1/MSCHAPv2 hashes, however, since they contain a unqiue challenge. Due to a design flaw, we can quickly recover two bytes of the underlying NT hash and use that as a crib to accellerate a rainbow-table style lookup against a pre- processed dictionary. The end result is a speedup of about 65,000 times over a plain dictionary attack in Python...not that I'm suggesting Python-based dictionary attacks are exactly fast. If Challenger cannot find the relevant password, it outputs a hash compatible with Moxie Marlinspike's CloudCracker.com website which should always be able to recover the full NT hash for you.

Setup

Before running challenger, replace wordlist.txt with a larger word list and execute rtchallenge.py to build the tables.

Use

challenger.py challenger.py '' challenger.py [-t | --test] (demo mode)

For rainbow table-like attacks, use rtchallenge.py to generate the appropriate rainbow tables and store the rainbow directory in the same directory as ./challenger.py.

Please ensure you use single quotes (') when passing a CloudCracker/Chapcrack hash to Challenger in a *nix system, otherwise the '$' get interpreted as signifying environment variables.

Author

Challenger was created by Tim Ehrhart (tehrhart@gmail.com), just for fun.

Copyright 2013 by Tim Ehrhart

Licensed under the GPLv3: http://www.gnu.org/licenses/gpl-3.0.