Trojans are the most active malware type in February

Trojans accounted for 23.70% of infections registered by ActiveScan, Panda Security’s online scanner, in February. However, the infections caused by this type of malicious code seem to have stalled over the last few months, compared to the constant growth witnessed in 2007.

Worms, however, have increased for the second month in a row, going from 15% to 17.60% Adware stayed at its usual level (20.71% of infections in February).

The worm boom is caused by an increase in their capabilities. Until recently, most worms were solely designed to spread from one computer to another. Over the last few months, however, there has been an increase in the number of worm strains capable of stealing data, something that, in the past only Trojans and spyware were capable of. This hybridization process is making it increasingly difficult to classify malware specimens into one category or another.

As for the most active malicious code in February, the list is headed by the Downloader.MDW Trojan, designed to drop other malware strains onto the infected computer.

The Bagle.RC worm takes second place, whereas the Lineage.GXD worm, designed to affect users of the Lineage online game is third.