UK security company Sophos has reported a significant decrease in emails containing viruses and worms, as hackers have shifted to using Trojans for more selective attacks. However, the Netsky.P worm remains at the top of the ranking for the most dangerous variants over the past 31 days.
Netsky.P, first discovered in March 2004, continues to be the most widely distributed program via email. The “team” of Mytob worms has also infiltrated numerous computer systems worldwide, with five variants appearing in the rankings.
May is still regarded as the month of “Trojan horses,” as this type of malware accounted for 85.1% of the 1,538 new threats recorded, bringing the total number of variants detected by Sophos to 122,634. In May 2005, one in every 38 emails contained malicious software; however, this rate has now decreased to one in 141.
“People should not look at Netsky.P’s top position and the number of infected emails and assume that dangerous software is merely a thing of the past. Cybercriminals today are even more cunning and crafty. They use spyware technology to probe businesses and individuals first, then attack specific targets,” commented Carole Theriault, a security advisor at Sophos.
The 10 Most Dangerous Viruses in May 2006 (with the reporting rate received by Sophos in parentheses):
1. Netsky.P (16.7%)
2. Zafi.B (11.4%)
3. Nyxem.D (7.5%)
4. Mytob.AS (6.3%)
5. Mytob.P (5.3%)
6. Mytob.M (5.3%)
7. Netsky.D (3.7%)
8. MyDoom.O (3.6%)
9. Mytob.FO (2.9%)
10. Mytob.C (2.1%)Others: 35.2%
T.N.
