Facebook Worm

Koobface ultimately attempts, upon successful infection, to gather sensitive information from the victims such as credit card numbers.
Koobface spreads by delivering Facebook messages to people that are 'friends' of someone on Facebook whose computer has already been infected. The messages contain innocuous subject headers such as "Paris Hilton Tosses Dwarf On The Street", "LOL", and "My friend catched you on hidden cam".Upon receipt, the message directs the recipients to a third-party website unaffiliated with Facebook where they are prompted to download what is purported to be an update of the Adobe Flash player. If they download the file, they will infect their computer with Koobface.