PC-Pro
Sophos's virus chart for February revealing spamming power has dramatically increased, putting figures for a spammed out Trojan in eighth place.
The remaining places in the chart are taken by self-replicating worms that often use their own email engines to send themselves on.
Clagger-G, however, holds its chart position entirely because it has been spammed out in vast numbers. And given that it was only first reported 13 February, it has spread incredibly rapidly in just two weeks.
'In order for this Clagger Trojan to make an appearance in the top 10, it must have been spammed out to millions and millions of email addresses worldwide,' said Carole Theriault, senior security consultant at Sophos. 'Trojan horses, which cannot spread on their own, account for roughly two-thirds of all reported malware. Rather than mass bombardment, most Trojan creators focus on small targeted groups to pilfer cash and sensitive information.'
Indeed this is the case with Clagger-G. Like many Trojans, Clagger-G sits quietly on an infected system and opens a backdoor through which it downloads malicious code able to monitor Internet and keyboard activity and send its findings back out to remote servers.
The most virulent virus in February was Netsky-P, still infecting systems almost exactly two years after it was first spotted.
The Karma Sutra worm, or Nyxem-D, with its file-destroying payload was a more recent threat and holds the number two position. The remaining places are taken by Netsky, Bagle and Mytob variants.
Sophos says that more than 1 per cent of all email was viral in February. The full chart follows:
1. Netsky-P 13.9%
2. Nyxem-D 9.3%
3. Bagle-Zip 8.8% Re-entry
4. Zafi-B 8.4%
5. Mytob-FO 6.0%
6. Mytob-EX 3.7%
7. Bagle-CH 2.7% New entry
8. Clagger-G 2.6% New entry
9. Netsky-D 2.4%
10. Mytob-BE 2.3%