Good Gear Guide
In Pictures: 20 notorious worms, viruses and botne...
The Flashback Trojan, discovered in 2011, affects computers running Mac OS X and exploits a security flaw in Java in order to install itself on Macs.
Blue Coat's Larsen notes Flashback is a "wake-up call for Mac users; no one should be feeling smug and safe these days."
In Pictures: 20 notorious worms, viruses and botnets