source: http://www.securityfocus.com/bid/552/info

Autothenticate is an extension for MacOS that remembers usernames and passwords from visited websites, and atomatically enters them when the site is visited again. It can be configured to store the username and password, the username only, or nothing. It stores this information in encrypted form in a preference file called "AutothenticatePreferences" located in the Preferences folder in the System Folder. The encryption mechanism used is weak and can be broken. 

This program, written by mSec, decrypts the Autothenticate information. 

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/19438.sit