Spyware is literally evolving — mutating in the wild to avoid detection. This is an ominous trend, and it’s getting worse: Cases of mutating spyware have more than doubled since the start of the year. And this is true mutation, unlike simple polymorphism. Impressive though it may sound, a polymorphic threat simply has multiple strains or chooses its name or location at install time, normally from a preset list. Most “mutating” malware in recent years has used these primitive techniques, which even basic signature-based solutions could handle with simple heuristics.