One in every 22 e-mails circulating across the internet is infected with the dangerous Sober-N worm, according to anti-virus experts. Specialists at software provider Sophos' virus and spam analysis centres have warned that the new worm is accounting for 79% of all viruses caught by its worldwide monitoring stations and shows no signs of slowing down. “This is one of the biggest virus outbreaks of the year,” said Graham Cluley, senior technology consultant at Sophos. Cluley said that the worm, which has been reported in 40 countries after its first appearance on Monday, appears to deactivate both Symantec's anti-virus protection and Window's XP's personal firewall, setting the stage for future attacks on the computer. Most likely, he said, the worm is preparing computers as hosts for distributing spam. Sophos' experts have calculated that 4.5% of all e-mail sent across the internet, whether legitimate or not, contain the Sober-N worm. It often appears, Cluley said, in the form of an offer for free tickets to the World Cup Championship in Germany next year.

“Many people found the prospect of free tickets to the prestigious sporting event just too hard to resist,” Cluley said. “No one should be fooled into thinking that e-mail viruses are a thing of the past.”