Sophos Security recently released its report on the top 10 most dangerous viruses for October. According to the report, Netsky has officially stepped down as the “champion” after dominating the rankings for nearly four consecutive months, making way for a familiar name – Sober. 
The Sophos report indicates that although Sober-Z was only discovered around the end of November, it quickly surpassed veteran competitors to dominate the November rankings.
Sophos statistics reveal that for every 13 emails sent, one contains Sober. The rapid emergence of Sober-Z has swiftly dethroned the “reign” of Netsky-P, which had held the top position for over four months, pushing Netsky down to second place.
The new variant of Sober-Z now accounts for 42.9% of all reported virus infections sent to Sophos, and it has the ability to send a copy of itself as an attachment in emails to addresses saved in the user’s contact list once it infects the user’s computer. Furthermore, Sober-Z actively attempts to disable security software on the user’s computer, significantly enhancing its spread.
Once the user opens the attachment, Sober-Z immediately activates and begins scanning the infected computer’s hard drive for email addresses to self-replicate and send copies to those addresses.
Carole Theriault, a senior security consultant at Sophos, stated, “Since we first detected Sober in October 2003, it is clear that the author of this virus has made significant efforts to improve tactics to trick users into opening emails containing Sober. This latest variant impersonates notifications from the FBI and CIA, alleging that the user has accessed illegal websites.”
The Sober virus also operates in two languages – English and German. In addition to imitating notifications from the CIA and FBI, it has a German version that includes a message stating “Who Wants to Be a Millionaire?” as well as impersonating information about American celebrity Paris Hilton.
Alongside Sober in this month’s rankings, familiar names such as Netsky, Mytob, and Zafi continue to dominate together. This indicates that virus authors are consistently creating new, highly effective variants for financial gain.
The Mytob family continues to demonstrate its wide and far-reaching spread with multiple variants occupying five positions on the top 10 most dangerous viruses list for November.
It can be said that recently, hackers and virus authors are placing greater emphasis on the quality of viruses rather than quantity. Today’s viruses spread more rapidly and pose a greater threat than before.
Top 10 Most Dangerous Viruses for November
1. New W32/Sober-Z (42.9%)
2. W32/Netsky-P (8.1%)
3. W32/Mytob-GH (6.8%)
4. W32/Mytob-EX (4.5%)
5. W32/Zafi-D (4.0%)
6. W32/Mytob-BE (2.3%)
7. W32/Zafi-B (2.1%)
8. W32/Mytob-AS (1.6%)
9. W32/Netsky-D (1.2%)
10. W32/Mytob-C (1.1%)
Other (25.4%)
