a bad scareware is Antivirus 2009 (microsoft). They take over and it is actually redirecting you to[removed site]and they want almost 50 bucks to fix the issue that they caused! Shuts down reliable access to your web browser , thus you can't get the patch. I had to revert and losses were painful. Lesson learned.

Be careful as it is not from the authentic MS Antivrus, but is merely masquerading as it.