Why they do it

If you got a computer virus ten or fifteen years ago, you probably experienced the digital equivalent of a mean and nasty practical joke: ink poured on important papers, stink bombs, bags of dog poop on fire, insults spray-painted on your house, your car keyed. Generally, virus/worm authors wanted notoriety, a rush of power, or just to stick it to someone who wronged them.

Now, it's all about cash money.

The Conficker worm recently woke up, as you may have heard. No, it's not the end of the world, but we are starting to see some of what it's designed to do- make money fast. Infected Windows machines are starting to present notices along the lines of "Hello. Your computer is infected. For $49.95, you can be cleaned!"

Malware authors are not maladjusted teens living in their parents' basement; they are professional criminals trying to make money.