3 January 2002 Despite the lack of a high profile virus such as ‘Melissa’ or ‘LoveBug’, more users than ever are becoming infected with computer viruses, according to email scanning service MessageLabs.

During 2002, one in every 212 emails scanned by MessageLabs contained a virus, compared to a rate of one in 380 in 2001 and one in 790 in 2000.

The most active virus in 2002 was the Klez worm, which exploits known vulnerabilities in the Microsoft Outlook email client. At its most infectious, MessageLabs claims to have found it in one in 268 emails scanned and it remains the most prevalent virus intercepted by MessageLabs, according to its December 2002 statistics.

However, at its October height, Bugbear was the most virulent virus of 2002, being found in one in every 87 emails stopped by MessageLabs.

The two most dramatic outbreaks recorded by the company remain Melissa and LoveBug, which infected one in every 28 emails in May 2000. “The more prevalent viruses this year have been the ones most people have found hardest to spot – like Klez and Bugbear,” says Alex Shipp, senior antivirus technologist at MessageLabs.

Part of the reason for the dramatic rise in infection rates is the increasing number of home users who have gone online in recent years, yet lack any form of virus protection software because of the cost. In addition, because viruses often run surreptitiously in the background, many do not even realise that they are infected.

Furthermore, such users often remain ignorant of the need to install the latest security patches for their software, particularly Microsoft Outlook – or lack the bandwidth to download them.