MyDoom is the 'worst ever' virus

It's only two days old and still growing fast, but at least one security firm is ready to crown the MyDoom virus as the worst ever.

Finnish security software and services company F-Secure made the coronation late Wednesday, declaring the MyDoom the fastest-spreading worm ever and "the worst email worm incident in virus history" in a letter research director Mikko Hypponen wrote.

MyDoom crawled onto the Internet on Monday, quickly clogging email servers, as it propagated itself with millions of messages laden with malicious software code. An offshoot of the pest surfaced Wednesday but did not appear to be spreading nearly as quickly as the original.

F-Secure estimated that the worm was accounting for 20 per cent to 30 per cent of worldwide email traffic Wednesday, putting it well ahead of previous nasties, such as the SoBig.F worm.

F-Secure credited the worm's fast spread to several factors, including aggressive harvesting of email addresses and the fact that it was released in the middle of the North American workday, giving it several hours to spread unchecked among corporate networks.

Other security companies had evaluations almost as dire. MessageLabs said it had intercepted more than 3.4 million copies of MyDoom, which infected one of every 12 messages, at its peak. That compares with a total of 33 million infections and a peak rate of one in 17 for SoBig.F.

David Becker writes for News.com