BozoCrack is a depressingly effective MD5 password hash cracker with almost zero CPU/GPU load. Instead of rainbow tables, dictionaries, or brute force, BozoCrack simply finds the plaintext password.
It works way better than it ever should.
Basic usage:
$ ruby bozocrack.rb my_md5_hashes.txt
Example with output:
$ ruby bozocrack.rb example.txt
Loaded 5 unique hashes
fcf1eed8596699624167416a1e7e122e:octopus
bed128365216c019988915ed3add75fb:passw0rd
d0763edaa9d9bd2a9516280e9044d885:monkey
dfd8c10c1b9b58c8bf102225ae3be9eb:12081977
ede6b50e7b5826fe48fc1f0fe772c48f:1q2w3e4r5t6y
To show just how bad an idea it is to use plain MD5 as a password hashing mechanism. Honestly, if the passwords can be cracked with this software, there are no excuses.
BozoCrack was written by Juuso Salonen, the guy behind Radio Silence and Private Eye.
Do whatever you wish. Public domain, yadda yadda.