New viruses up the stakes on old tricks

Spring was a notable season in the virus world as Klez edged out SirCam as the all-time most virulent virus, and another virus landmark emerged with Simile.D - a polymorphic, entry-point-obfuscating virus that can infect both Windows and Linux platforms. Unlike the costly and destructive Nimba and Code Red viruses, Klez and Simile.D are more nuisance than financial nightmare. Nonetheless, they represent emerging challenges for antivirus developers. Both of these complex viruses take previous tricks to a new level, either by expanding their infection potential, at least in theory (Simile.D), or by combining multiple best-tricks into one insidious package (Klez).