What version of Firefox are you running. (To find out click “Help” then “About Mozilla Firefox”).
I’m running v. 3.6.17 but it wants me to download v. 4.0.1. I’m resisting because some of my useful add-ons are always disabled when I upgrade versions so probably will stay with what I have until they stop issuing security updates.
I am using Microsoft Security Essentials.
This isn't a virus. It's an application. Security Essentials warned me that Firefox wanted to make an exception on the firewall, and I allowed it. It was my fault. I have never seen a browser application ask to breach the firewall. I should have known better. It will never happen again.
I tried FF 4 but I’m getting annoying page freezes. I have to move the mouse while I using the down button to scroll. I’ll probably go back to 3 something...