Sasser tops virus infections
However, six variants of the Netsky worm also broke into the top ten, reminding network administrators to still be on the lookout for versions of the troublesome virus.
Carole Theriault, security consultant at Sophos, said: "Sasser was the major pain in the neck this month, affecting far more users than even the prevalent Netsky worms. Requiring no user intervention and taking advantage of a relatively new Microsoft hole, it sneaked onto unprotected PCs, swamping internet connections."
Theriault believes effective patch management and user education are still two factors sorely lacking from companies' antivirus policies and urged firms to rectify this situation.
The top ten of viruses in May 2004 looks like this -- figures given as percentages represent share of total virus reports:
- 1. Sasser (51.1 per cent)
- 2. Netsky-P (11.7 per cent)
- 3. Netsky-B (4.1 per cent)
- 4. Netsky-D (3.8 per cent)
- 5. Netsky-Z (3.4 per cent)
- 6. Netsky-Q (2.4 per cent)
- 7. Netsky-C (2.1 per cent)
- 8. Sober-G (1.5 per cent)
- 9. Bagle-A (0.8 per cent)
- 10. Lovgate-V (0.7 per cent)