On Sunday 8/30 one of my computers got hit with Personal AntiVirus. This computer has been running Norton Internet Security 2009 continuously for almost a year and the software and virus definitions are completely up-to-date. Yet still, Personal AntiVirus was allowed to be installed on that computer. And a full system scan by Norton IS failed to detect it, let alone remove it. I finally got rid of the PAV virus by dowloading and running the free version of Malwarebytes' Anti-Malware. This was a real pain because PAV was also blocking IE8 from accessing the Malwarebytes' download page.
Anyway, all is well now, but my question is this - why does Norton Internet Security fail to detect this virus and instead, allows it to be installed on a computer that is presumably being fully protected against such threats? And why is it necessary to use a free application to do a job that should have been done by Norton IS ? Norton should be paying Malwarebytes for cleaning up the messes that their own software fails to prevent. I only have about 50 days left on my Norton IS subscription, and unless I can get some assurance that this was a very unusual event I think I will look elsewhere (like ZoneAlarm) for my next AV program.