Top Ten Viruses Reported To Sophos In December 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 December 2001, the chart is as follows, with the most frequently occurring virus at number one:

1. W32/Badtrans-B (Badtrans variant) – 92.4%

2. W32/Goner-A (Goner variant) – 1.0%

3. W32/Magistr-B (Magistr variant) – 0.9%

4. W32/Sircam-A (Sircam variant) – 0.7%

5. W32/Magistr-A (Magistr variant) – 0.5%

6. W32/Hybris-B (Hybris variant) – 0.3%

7= W32/Nimda-A (Nimda variant) – 0.2%

7= W32/Sheer-A (Sheer variant) – 0.2%

7= W32/Nimda-D (Nimda variant) – 0.2%

7= W32/Apology-B (Apology variant) – 0.2%

Others – 3.4%

“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.

For more information about Badtrans, please visit:

Graphics of the above Top Ten chart are available at:

For more information about safe computing visit:

Compiled by Sophos’s technical support team, the top ten chart is collated from submissions to Sophos’s 24 hour, 365 days a year technical support service.


Sophos is one of the world’s largest specialist developers of anti-virus software. The products are sold and supported through a global network of subsidiaries and partners in more than 150 countries. Sophos Anti-Virus is widely used by large corporations, banks and governments.

For further information, please visit

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For more information, contact Natasha Staley on 01235 544160.

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