Magada's Journal: Microsoft - Patent troll or legitimate innovator?

Ars Tehnica reports that Romanian antivirus makers BitDefender, along with many others, may find themselves in a spot of hot water over Microsoft's recently granted patent no.7376970 which apparently describes the workings of a pro-active heuristic antivirus operating in a virtual environment.
The patent was filed in the name of one Adrian Marinescu, who came to Microsoft as a result of the deal by which Microsoft acquired the antivirus division of Gecad, another Romanian company. Only time will tell if Microoft intends to use this patent offensively or defensively.
Prior art, anyone?