Bugbear puts Klez in the shade

Anti-virus firms have warned that Bugbear is fast becoming the most prolific virus of the year - eclipsing even Klez, which has been top of the virus charts for the past six months.

Bugbear has been cropping up in email inboxes worldwide for the past week and is already poised to take its place among the virus greats, such as Klez, the Love Bug and Melissa.

Email service provider Messagelabs, which hosts email servers around the world, said it intercepted 66,000 messages infected with Bugbear on Friday, with levels falling to 35,000 on Saturday and 34,000 on Sunday as business users logged off.

But many people will have returned to work today and will have opened up their Outlook inboxes this morning to find they have received other people's private emails, ranging from personal email conversations to hotel bookings and transaction receipts - many containing personal data - which have been redistributed by the virus.

Anti-virus firm Sophos has even had to switch to a low-graphics version of its website in response to massive demand for information on the prodigious virus.

In a posting on the site, Graham Cluley, senior technology consultant at Sophos, said: "We have seen a spurt of new activity as people have returned to work on Monday morning and opened their email. We have also seen reports from many home users who used their unprotected computers at the weekend."