20 notorious worms, viruses and botnets

Conficker

Credit: CSO Staff

The massive number of machines infected by Conficker got everyone's attention, says Haley. The real interesting thing about it, though, and what caused even more fear was the great unknown: What would happen when the resulting botnet woke up on a date specified in the threat's code.

Fortunately, it did not live up to people's worst expectations.