Wired Science

What’s the Cost of a Hijacked Computer?

Botnets—networks of "zombie” computers that have been hijacked to perform dirty tasks—aren't just for computer whizzes anymore. Today, people who know how to do little more than check their e-mail can rent botnets on the black market to send out spam, jam up competitors' websites, and even monitor people's keystrokes in the hopes of detecting their passwords. Although estimates vary, botnet rentals might set you back about $1,000 per spam or DDoS (distributed denial of service) event—in other words, for about a day or two of usage.

There are other potential costs, too. After all, where do cybercriminals get the computers to build up their botnets in the first place? The more botnets there are around—and the more they are in demand—the more likely it is that your own computer will be recruited unknowingly. Although estimates vary, some computer security experts believe that upwards of one out of every 10 computers connected to the Internet is unknowingly being used as part of a botnet.