Koobface started life compromising Twitter accounts. It then diversified
to attack various social networking sites including Facebook, MySpace, Bebo, hi5, GeoCities, Friendster among the prominent ones.
Recently I came across what could possibly be the next iteration of Koobface, W32/Koobfa-O
, which came with Skype hacking functionality and some additional promises for the future. The new variant of Koobface attacks Skype accounts on the compromised machine to get various pieces of information about the victim using the different Skype API commands.