hashcat

Offline Password Cracking: The Attack and the Best Defense

Offline Password Cracking is an attempt to recover one or more passwords from a password storage file that has been recovered from a target system.  Typically, this would be the Security Account Manager (SAM) file on Windows, or the /etc/shadow file on Linux.  In most cases, Offline Password Cracking will require that an attacker has already attained administrator / root level privileges on the system to get to the storage mechanism.