It’s not exactly a secret that Facebook is a breeding ground for viral scams. With close to 700 million users — many of whom are unwary and not-so-computer-savvy — the social networking site provides ample opportunity for cybercriminals to hawk their (mal)wares.
http://www.geek.com/articles/news/facebook-like-exploited-to-spread-windows-and-mac-malware-2011061/