During an 18-month-long hacker °attack in 2009-2010, Facebook users were tricked into revealing their passwords and downloading a rogue program that steals financial data. A legitimate-looking Facebook e-mail notice asked users to provide-information to help the social network update its login system. When the user clicked the "update" button in the-e-mail, that person was directed to a bogus Facebook login screen where the user's name was filled in and that person was prompted to provide his or her password. Once the user supplied that information, an "Update Tool" installed the Zeus "Trojan horse" rogue software program designed to steal financial and personal data by surreptitiously tracking users’ keystrokes as they enter information into their computers. The hackers stole as many as 68,000 login credentials from 2,400 companies and government agencies for online banking, social networking sites, and e-mail.