A new virus called Backdoor.K0wbot.1.3.B replicates itself, infecting KaZaA users who unknowingly download an infected file. Backdoor also infects via the IRC remote-control backdoor component -- hence the name. As "Tech Live" reports tonight, Backdoor is not the first virus to infect KaZaA users and is a reminder of the risk of infection that can sometimes come with using file-sharing services.

The Benjamin worm hit file swappers in May. Benjamin also disguises itself as media files and uses the infected computer as a host to spread itself to other unsuspecting peer-to-peer downloaders.

Once executed, Backdoor can gain control of a victim's computer. Specifically, the the code can update the virus by downloading a newer version, reporting information about the infected system -- CPU speed, memory, operating system version, uptime, Internet connection type, local IP address. It also reports installed software and performs different IRC commands, including flooding other users of the chat server.

"This backdoor is the second virus to successfully attack the popular network in less then two months," said Bogdan Dragu, virus researcher at BitDefender. "Following this trend, peer-to-peer file-swapping networks could soon become a paradise for any virus writer."

On computers running the KaZaA software, Backdoor replicates copies of itself, making hundreds of copies and renaming them as tantalizing media downloads.

Security firm BitDefender has a free removal tool available for download.