We have already seen a file infector working on smartphones (see WinCE.Duts.A) and a worm that could spread by infecting storage cards (see WinCE.Infomeiti). Now, we have the first polymorphic worm (although some refer to it as a companion virus) that affects smartphones running Windows CE platform on ARM processors—it is known as WinCE.Pmcryptic.A. It spreads by generating new polymorphic copies of itself each time, and can cause a severe nuisance on a compromised phone (including unwanted phone calls to toll numbers).
After analyzing the sample, we discovered it contained many interesting payloads. So, we executed it on a test...