LC 5 optimizes operations by first scanning for dictionary words, then using various methods of altering dictionary words to create new probable guesses, then (if all else fails) resorting to brute force. To crack a password, the program must select a guessed word, compute the hash, then compare that hash with the stored password hash. LC 5 supports direct hash imports from a local or remote SAM database, a SAM file, an LC 4 file, a PWDUMP file, a Windows NT 4.0 Emergency Repair Disk (ERD), a UNIX password file, or by sniffing the local network. To speed the hashing process, most versions of LC 5 include precomputed hashes and let you create your own precomputed hash tables. During the audit, the tool shows time elapsed and other statistics.
LC 5 also lets you disable accounts or force users to reset weak passwords.