May 9, 2012 at 4:50 PM ET
Cybercriminals know what works, and in the first three months of this year, Trojans are doing the job.
In PandaLabs' Quarterly Report, the security firm identified more than 6 million new malware samples between January and March, 80.77 percent of which were Trojans. This is a new record, and a continuation of a growing trend. As Trojan armies increase, researchers said former top-tier threats must make way.
"While, as expected, Trojans account for most infections, it is worth noting the relatively small number of PCs infected by worms, which is lower than the number of new worms created over these three months," the researcher said. "This demonstrates that massive worm epidemics have become a thing of the past, and have been replaced by a silent Trojan invasion."
The classic definition of a Trojan is a piece of malware that pretends to be a benign file or program, like a movie player or PDF, and doesn't replicate itself the way a virus or worm does. Malware definitions have become blurred as cybercriminals innovate, and many Trojans are today just parts of larger "exploit kits" that bombard Internet-facing software with one piece of malware after another until something gets through.
The particular Trojan PandaLabs profiled in its report is the " Police Trojan," which presents victims with a fraudulent message claiming to be from the U.S. Department of Justice informing them that they've violated laws by looking at child pornography and must pay to have their computers unlocked.
PandaLabs analyzed which countries have been most affected by malware, and found that China leads the list, with 54.10 percent of its PCs infected. Thailand (47.15 percent) and Turkey (42.75 percent) came in second and third, followed by Russia, Peru, Ecuador, Spain, Argentina, Poland and Chile. The average number of PCs infected worldwide is 35.51 percent, which is less than 2011, researchers said.