Dorf worm storms the top ten malware chart

Sophos has revealed the most prevalent malware threats and email hoaxes causing problems for computer users around the world during January 2007.

The figures, compiled from Sophos’s global network of monitoring stations, show that the recently discovered Dorf malware has had a massive impact on computer users worldwide, rampaging to the top of the monthly malware threat chart and accounting for almost 50 percent of all malware seen during January.

The Dorf malware was aggressively spammed out posing as breaking news of deaths caused by stormy European weather during January. Later in the month the authors changed tack and launched a further campaign disguising the malware as a romantic email greeting card. Elsewhere in the top ten, the Netsky, Mytob and Stratio malware remain rooted in second, third and fourth place respectively, between them accounting for one third of all malware reports.

The top ten list of malware threats in January 2007 reads as follows:



 1.    Dorf            46.1%

 2.    Netsky          16.1%

 3.    Mytob            9.8%

 4.    Stratio          8.5%

 5.    Zafi             3.6%

 6.    MyDoom           2.8%

 7.    Sality           2.6%

 8.    Bagle            2.5%

 9.    Nyxem            1.0%

10.    Wukill           0.8%



       Others           6.2%

Sophos has so far seen more than 2500 variants of the Dorf malware – almost a third of the new threats identified during January 2007. The majority of these variants were intercepted by Sophos’s proactive Behavioral Genotype Protection technology even before they were formally identified as belonging to the Dorf family of malware.

The proportion of infected email, while substantially higher than in December 2006, is still small at just one in 238 (0.42%), while during January Sophos identified 7,272 new threats, bringing the total number of malware protected against to 214,956.

The top ten hoaxes and chain letters in January 2007 were as follows:



 1.    Hotmail hoax                 28.8%

 2.    Olympic torch                16.9%

 3.    Justice for Jamie             3.1%

 4.    Budweiser frogs screensaver   2.9%

=4.    A virtual card for you        2.9%

 6.    Bonsai kitten                 2.5%

 7.    Applebees Gift Certificate    1.7%

=7.    Meninas da Playboy            1.7%

 9.    Bill Gates fortune            1.4%

10.    MSN is closing down           1.3%



       Others                       36.8%