The hybrid Trojan/worm malware deployed to gullible Internet users has caused quite a stir in February, according to the latest statistics from Panda Security, formerly known as PandaLabs. The lethal duo coming in one package has comprised 17.6 percent of the total infections happening in the passed month, 2.6 percent up from the January metrics.

"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," said Luis Carrons, technical director of the security company. The canny filters catching the malware have an increasingly difficult task because of the increasing number of malicious code floating around, and because it is getting more sophisticated with every day passed.

Trojans alone have accounted for 23.7 percent of the infections and fortunately have remained constant around that number, with only slight differences in the decimal area changing in since the monitoring began. "Over the past few months, however, there has been an increase in the number of worm strains capable of stealing data, making it increasingly difficult to classify malware specimens into one category or another," Carrons pointed out.

PandaLabs have put together some of the most active malware samples in February:

1. Trojan Downloader.MDW
2. Worm Bagle.RC
3. Worm Lineage.GXD
4. Worm Bagle.RP
5. Worm Lineage.HJT
6. Worm Perlovga.A
7. Worm Bagle.HX
8. Worm Lineage.HIC
9. Worm Puce.E
10. Worm Lineage.HJB

Downloader.MDV was specifically designed to drop additional malware strains on the infected computer, aside from turning it into a zombie, part of a botnet. The last on the list, Lineage. HJB is a worm that only affects users of the Massively Multiplayer Online Role-Playing Game, cunningly hiding itself by deleting the original file from which it was run, once it is installed on the computer.