"Koobface" a Threat to Social Networking Site Users
The "Koobface" worm has resurfaced and security experts have issued warnings to users of social networking sites including MySpace and Facebook regarding this renewed threat. Users should beware of messages that may direct them to a counterfeit YouTube site, which prompts them to install what appears to be an Adobe Flash update. The installed software turns out to be a Trojan virus which propagates itself by sending similar messages to friends of the user whose machine has been newly infected. Users of compromised machines may find that when they try to use search engines including Yahoo, Google, MSN and Live.com they are redirected to contaminated sites.
Security experts have also advised of fake Facebook sites and “rogue” apps advising users of an error with their account or that they had been reported for violating Facebook's terms of service. These fake sites prompt for the Facebook user's username, password and other personal information. The compromised Facebook credentials are then used to send fraudulent messages to other Facebook users.
To avoid becoming the victim of “Koobface” and similar attacks, users should always be careful about links in messages, even if they appear to be from friends. Users should also research any application or purported update to that application to verify its legitimacy before installing it.
http://main.uab.edu/Sites/it/announcements/63965/