In Pictures: 20 notorious worms, viruses and botnets

The earliest worms and viruses were created for geeky fun and did little harm - oh, how times have changed. Here are 20 worms, viruses and botnets that show the evolution of malware, from Creeper to Flame.

Flashback

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."

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