AddAntivirus.com is the latest browser hijacker, whcih was designed to promote the rogue anti-spyware application, MS Antispyware 2009 (MSAntispyware2009). This is still same bogus application. You can get infected with AddAntivirus.com hijacker by visiting infected sites or by download of torrents infected with this malware. After installation, you are redirected to AddAntivirus.com where all you can do is either download the fake scanner or purchase the rogue application. Should you be duped into buying the application MS Antispyware 2009 (MSAntispyware2009), you should be prepared fo rhte fact that your credit card details will be given away to the makers of this rogue application. The best thing to do would be to block these dubious domains like AddAntivirus.com from your browser – thsi way oyu will not be subjected to their dubious antics,