L0phtCrack is a password
auditing and recovery application
. It uses multiple assessment methods to assist administrators in reducing security
risks. L0phtCrack helps to identify and remediate security vulnerabilities that result from the use of weak or easily guessed passwords and recover Windows and Unix account passwords to access user and administrator accounts whose passwords are lost or to streamline migration of users to another authentication
system. Additionally, some versions of L0phtCrack can process accounts using pre-computed password tables that contain trillions of passwords.