Hackers have created a new technique for compromising computers that totally evade signature-based anti-virus detectors.
http://www.infoworld.com/article/07/08/03/Malignant-Javascript-mutates_1.html
[Editor's Note (Valle): As hackers find more and more ways to outsmart signature-based A/V technologies, behavioral-based A/V technologies like CSA are no long "nice to have" as an extra layer of defense. The are a "must have".]