Kaspersky Virus Top 20 for January.

Pos. Virus % 1. Email-Worm.Win32.NetSky.q 27.22 2. Email-Worm.Win32.Nyxem.e 12.23 3. Email-Worm.Win32.Bagle.gt 9.27 4. Email-Worm.Win32.NetSky.aa 7.39 5. Email-Worm.Win32.Scano.gen 6.19 6. Trojan-Downloader.Win32.Diehard.dg 4.32 7. Trojan-Dropper.Win32.Small.bdj 3.54 8. Email-Worm.Win32.NetSky.d 2.92 9. Net-Worm.Win32.Mytob.w 2.79 10. Email-Worm.Win32.Warezov.yi 2.50 11. Net-Worm.Win32.Mytob.q 2.40 12. Email-Worm.Win32.NetSky.y 2.10 13. Troj an-Downloader.Win32.Diehard.dh 1.98 14. Email-Worm.Win32.Bagle.gen 1.69 15. Email-Worm.Win32.NetSky.t 1.40 16. Net-Worm.Win32.Mytob.t 1.26 17. Email-Worm.Win32.Mydoom.l 1.16 18. Email-Worm.Win32.Scano.bn 0.97 19. Troj an-Downloader.Win32.Diehard.dj 0.94 20. Trojan-Downloader.Win32.Diehard.dk 0.90 Other malicious programs 6.83

For the second month in a row, representatives of the new Trojan-Downloader family Diehard have been creating a considerable stir in mail traffic. Our December 2007 Top Twenty contain three variants of this program; yet another variant has joined the rankings in the first month of 2008. The unknown authors are using exactly the same approach which made families such as Warezov and Zhelatin so successful two years ago--conducting a multitude of very short lived mass-mailings. However, in contrast to Warezov, we're not yet seeing ten new variants of Diehard every day.

All of this has a very interesting effect--older email worms end up occupying leading positions in the rankings. Two examples are NetSky.q, which seems to constantly head the Top Twenty, and Nyxem.e, which made it into second place in January. They are a constant presence in mail traffic, and it's always the same variants.

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