A general word of caution to all facebook users- considering its one of the most popular social networking sites, i guess is a general caution to all.
There are several worms doing the rounds on facebook – the most recent of them being the koobface.
the modus operandi is the same- send a link through a message, considering its coming from a friend, you tend to visit it, after that it downloads a trojan onto the system. Now the scary part is that its using the macromedia / activex route to run this exploit.
its asking for the update, its downloading a worm onto the system, and then when you visit facebook the next time, it gets your username / password and replicates itself. from the facebook account. It has appeared to have been more complext through a greater level of automation than before. So next time a message comes from a friend, please check the message before visitng the site.
More :
http://news.cnet.com/facebook-fights-new-koobface-worm-another-rogue-app/
http://www.techcrunch.com/2008/08/07/elaborate-facebook-worm-virus-spreading/