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01 Oct 2001

Top ten viruses reported to Sophos in September 2001

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

Position Last
Malware Percentage of reports

"Nimda attacks from every angle. It uses a multi-pronged method to exploit a number of known weaknesses," said Peter Cooper, UK support manager at Sophos Anti-Virus. "Despite the high profile warnings, it is continuing to infect people who have failed to update their virus protection."

"Ensuring your operating system is fully patched and updated is as important as up-to-date anti-virus software," continued Cooper. "Had the affected machines been patched up prior to infection, the path and magnitude of Nimda would have been very different."

890 new viruses were discovered and protected against by Sophos Anti-Virus during September 2001.

The total number of viruses Sophos now detects and protects against is 68111.

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.

About Sophos

More than 100 million users in 150 countries rely on Sophos as the best protection against complex threats and data loss. Sophos is committed to providing complete security solutions that are simple to deploy, manage, and use and that deliver the industry's lowest total cost of ownership. Sophos offers award-winning encryption, endpoint security, web, email, mobile and network security solutions backed by SophosLabs - a global network of threat intelligence centers.

Sophos is headquartered in Boston, US and Oxford, UK. More information is available at