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.

Koobface

Koobface (an anagram for Facebook) made headlines in 2008.

"It spread by pretending to be the infected user on social networks, prompting friends to download an update to their Flash player in order to view a video. The update is a copy of the virus," explains Lovet.

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