Researchers at the volunteer-run Shadowserver Foundation say the Conficker worm has now infected more than 7 million computers. InfoWorld reports that researchers have kept track of Conficker infections by cracking the algorithm the worm uses to look for instructions.

Still, the criminals who control Conficker rarely use it. Why is still a mystery, but Eric Sites, chief technology officer with Sunbelt Software, speculates:

The only thing I can guess at is the person who created this is scared. This thing has cost so many companies and people money to get fixed, if they ever find the guys who did this, they're going away for a long time.