Top ten viruses reported to Sophos in December 2001

Sophos Press Release

This is the latest in a series of monthly charts counting down the ten most frequently occurring viruses as compiled by Sophos, a world leader in corporate anti-virus protection.

For December 2001, the chart is as follows, with the most frequently occurring virus at number one:

Position Last
Malware Percentage of reports

"Badtrans dominated the figures for December 2001, accounting for 9 out of every 10 viruses reported to Sophos last month, and becoming one of the most widespread worms of the year," said Graham Cluley, senior technology consultant at Sophos Anti-Virus. "End of term fever may have hit businesses as users let down their guard. Once again this outbreak proves that users need to think before they double-click on unsolicited email attachments and ensure their anti-virus is kept up-to-date".

1256 new viruses were discovered and protected against by Sophos Anti-Virus during December 2001.

The total number of viruses Sophos now detects and protects against is 71,192.

More information about Badtrans</>.

More information about safe computing.

Graphics of the above Top Ten chart are available here.

Compiled by Sophos's technical support team, the top ten chart is collated from calls to Sophos's 24 hour, 365 days a year technical support line.

More than 100 million users in 150 countries rely on Sophos’ complete security solutions as the best protection against complex threats and data loss. Simple to deploy, manage, and use, Sophos’ award-winning encryption, endpoint security, web, email, mobile and network security solutions are backed by SophosLabs - a global network of threat intelligence centers. Sophos is headquartered in Oxford, U.K., and is publicly traded on the London Stock Exchange under the symbol “SOPH.” More information is available at