A tab popped up wich said Mozzilla Security, the web page seemed to scan my computer, stated it was infested with several viruses, and that I should download protection immediatly. Is this legit?
A new tab opened up on my tool bar labeled Mozilla Security. The website looks like your security warning. But the security button is gray, McAfee doesn't recognize the site, and the web address does not contain Mozilla.com. The web address of this pop up page is: http://update89.modyett.co.be/index.php?Q57hGtS5bW5G7Hr+M0lEZy4rE7T40TcfocDyRAcjpCPVLS/PhAEpv1Hgq9vgx1qxsLunLyiXHnwwL5T3qX/CE0Q/ZRXJp+2mKYsC+kRq
Do I have a virus, as it states, or is this uninvited web page trying to install a virus? What should I do?
Just because it said Mozilla Security in the title bar does not mean it is from Mozilla as Mozilla nor the Firefox browser has ever done such a thing.
This sounds like one of those fake animated scanners which claims it is scanning your computer and then says you are infected with such and such. It then suggests to download something that will be what really infects your computer if using Windows. As long as you did not download and install this whatever.exe then you should be safe. Though you may want to scan your computer with whatever antivirus software you have with updated definitions just to be safer.
This sort of thing is even more obvious on being fake when Linux and Mac users can encounter these pages.