Damn these Windows Virus Testers - Online

[Jim]

F14

Every so often I get one of these DAMN Windows Virus testers while 
Online with Firefox and I can't stop it , I have to do a 
ctrl-alt-backspace to get out of it. and even tho I long back in Firefox 
wants to automatically restart the test , without asking me if I want to 
Restore or Start New Session.

How can I prevent Firefox from Starting these tests ?  I don't want to 
change any settings that Will affect any other web site

It does not make any difference what Website your on it's just pops up 
and starts