Malware detections soared last year, with an increase of 172 percent from 2005, according to research from PandaLabs. Trojans showed the most substantial growth.
Large scale infections caused by a single virus are on the wane, but multiple variants silently infecting computers are on the rise, the study found.
Trojans are now the most prevalent form of malware, comprising more than half (54 percent) of all previously unseen malicious software detected last year. Bots were 14 percent of all new malware detected in 2006, and backdoors were 13 percent.
The annual report also found that hybrid malware increased last year. The current fusion between worms or trojans and rootkits highlight how difficult it is to distinguish among different malware groups, researchers at PandaLabs said.
"Users have a false sense of security, believing there are no dangerous threats. The truth is, however, that there is now more malware than ever," said Luis Corrons, technical director. "We have detected the same amount of malware last year as in the previous 15 years combined."
The motivation of cybercriminals during 2006 was once again financial, with the online sale of malicious programs thriving, according to the vendor.