Users of the Kazaa file-sharing network were today warned about the second virus in as many months to infect users.

The virus, known as the Kowbot worm, is able to take control of the victim's computer as well as update itself automatically and send information out from the host machine. It can also be used as a remote control internet relay chat (IRC) bot and to attack IRC chat servers.

The worm tricks users into downloading it by masquerading as appealing media files such as popular MP3s of films. Once it has infected a user's machine it makes 150 copies of itself in the Kazaa shared files directory in a bid to lure other victims.

Wary users may be able to spot the worm: all the files it pretends to be in the Kazaa directory are 19k in size, which may seem suspicious.

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

Back in May, millions of users were alerted after the Benjamin worm was found to be actively infecting users on the Kazaa network.