Researchers Count a Million Zombie PCs

The BBC has reported that there are as many as one million "zombie" PCs connected to the Internet. Zombies are machines that have been compromised by hackers and hijacked to carry out attacks against Web sites and spread malware and spam.

The BBC's report indicated that investigators spent several months tracking more than one hundred networks of remotely-controlled machines with the largest network being comprised of 50,000 home computers.

The research was conducted by a group called the "Honeynet Project."

During the monitoring, hijacking attempts were so pervasive that machines set up as "honey pots" to collect information were found by hijacking attack tools within minutes.

In one instance, a machine was compromised within seconds of being put online. Hijacking tools seek out commonly known vulnerabilities in operating systems for exploitation.

Researchers also observed 226 separate distributed denial of service attacks against 99 different targets.