The proportion of email messages infected with a computer virus increased by over 80 per cent in 2002. Experts blame the surge on a new trend involving email address forgery, which is designed to frustrate efforts to prevent a virus from spreading.
New data from MessageLabs, a UK anti-virus company, show that the proportion of emails carrying a virus has increased steadily over the past three years.
During 2002, one in every 212 emails passing through the company鈥檚 filtering system was a virus. This is nearly double the rate of one in every 380 recorded for 2001. And in 2000 the ratio was one in every 790 email messages.
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Alex Shipp, senior anti-virus technologist with MessageLabs, says 2002鈥檚 most virulent virus, Klez.H uses forged email addresses to subvert efforts to stops its spread.
Big hit
The virus automatically forwards itself to all the entries in a victim鈥檚 email address book, but doctors the email to make it appear as if it was sent from another address in the book, not from the real victim. 鈥淭hat鈥檚 been a very big hit this year,鈥� he told New Scientist. 鈥淭here are lot of other viruses that are trying the same trick.鈥�
Shipp believes the trick explains the success of Klez.H. MessageLabs, which provides email screening for UK companies, detected almost five million copies of Klez.H in 2002. The second most numerous virus was Yaha.E with just over a million copies.
Forging the address an email virus is sent from confuses attempts to track down the source of infection and halt its spread. A recipient may also blame an innocent party for forwarding on the virus.
And some anti-virus programs automatically alert a person thought to have sent a virus to warn them that their computer may be infected. In the case of Klez.H an alert would be sent to the wrong person. MessageLabs recently deactivated its own automatic alert system for this reason.