Netsky-P, the worm written by the convicted German teenager, Sven Jaschan, has yet again retained its position at the top of the Sophus-compiled list of Top Ten Viruses & Hoaxes causing problems for businesses around the world during the month of August 2005.

The report, compiled from a global network of monitoring stations maintained by Sophos, a world leader in protecting businesses against viruses, spyware and spam, reveals that  the recent Zotob worms are notable by their absence in the chart despite having received a great deal of press attention for successfully infecting several high profile media organisations.

The prevalence of the Netsky-P worm rose slightly in August, from 13.9% to 14.7%, but variants of the Mytob worm remain the dominant threat to computer users, accounting for 54% of all viruses reported to Sophos in August. In addition, research now suggests that the Zotob group of viruses is also directly linked to Mytob.

"Mytob and Zotob may spread in different ways, but the source code is very similar," said Carole Theriault, security consultant at Sophos. "Moreover, the Zotob author's nickname, Diabl0, appears in more than twenty of the Mytob variants, suggesting that they may have been created by the same person. One thing is for sure - Mytob is still causing chaos in organisations that haven't updated their virus protection and patched software vulnerabilities."

The top ten viruses in August were as follows (last month's position in brackets):

1. (1) W32/Netsky-P
2. (2) W32/Mytob-AS
3. (3) W32/Mytob-BE
4. (5) W32/Zafi-D
5. (Re-entry) W32/Zafi-B
6. (New) W32/Mytob-C
7. (4) W32/Mytob-EP
8. (6) W32/Mytob-CX
9. (7) W32/Netsky-D
10. (8) W32/Mytob-CJ

For Top Hoaxes see next page...