John the Ripper is a free password cracking software tool.

It can be run against various encrypted password formats including several crypt password hash types most commonly found on various Unix versions (based on DES, MD5, or Blowfish), Kerberos AFS, and Windows NT/2000/XP/2003 LM hash.

The third line is the command for running John the Ripper utilizing the "-w" flag.

Many of these alterations are also used in John's single attack mode, which modifies an associated plaintext (such as a username with an encrypted password) and checks the variations against the hashes.

This method is useful for cracking passwords that do not appear in dictionary wordlists, but it takes a long time to run.