Sophos has published a report revealing the top ten viruses and hoaxes causing problems for businesses around the world during the month of November.
The report, compiled from Sophos's global network of monitoring stations, shows that two new major viruses - Sober-I and Bagle-AU - appeared during the month, though the prevalent Netsky-P and Zafi-B, first spotted in March 2004 and June 2004 respectively, continue to be major irritants.
The top ten viruses in November 2004 were:
1. W32/Netsky-P 24.2%.
2. W32/Sober-I 20.4% NEW ENTRY.
3. W32/Zafi-B 17.9%.
4. W32/Bagle-AU 11.0% NEW ENTRY.
5. W32/Netsky-D 4.4%.
6. W32/Netsky-Z 3.9%.
7. W32/Bagle-AA 2.6%.
8. W32/Netsky-B 2.4%.
9. W32/MyDoom-O 2.2%.
10. W32/Netsky-Q 2.1%.
Sophos security consultant Carole Theriault said two new entrants made it into the chart last month - Sober-I and Bagle-AU.
“Sober-I's impact was particularly significant; it reached number two in the chart, accounting for over 20% of reports, even though it was not discovered until 19 November.
"Sober-I spreads by email and uses a variety of subject lines and message texts, many of which allude to important security or messaging information,” she said.
“This type of ruse often outwits users, who double-click on the attachment to learn about the problem. Instead of discovering more about the bogus issue, unprotected users are infecting their computers.
"Despite the appearance of Sober-I on the scene, relative old timers Netsky-P and Zafi-B have continued spreading, even though protection against them was made available as soon as they were first detected.
“Users can thwart these established threats by simply keeping their anti-virus protection up-to-date," she said.
Sophos analysed and protected against 1379 new viruses in November. The total number of viruses Sophos now protects against is 97,535. Sophos research shows that more than 5.6%, or one in 18 emails, circulating during the month of November were viral. This is an increase from last month's figure, which was 4.6%.
Sophos has available a free, constantly updated information feed for intranets and websites which means users can always find out about the latest viruses and hoaxes.