It has always been observed that autoplay/autorun feature of MS windows OS is one of the most preffered selection of malware propagation.We've witnessed some devastating examples of malware which used this feature effectively to replicate and converting a single machine infection to a malware outbreak with in first few hours.Conficker a.k.a W32.downadup is the most recent example of such malware.But this is not at all a new method of infection,rather this method of infection is there since decades.Some more popular examples are Trojan.Brisv.A!inf,W32.Gammima and many more in the long list.