Firefox 技術支援討論區

One of my tabs just crashed and I received a lengthy demand "Authentication Required" that I know nothing about. It requires my user name and password and the message is as follows: http://13-554x00001-virus.com is requesting your username and password. The site says: "Security Update Error 0xB7856713 Help Desk + 1 (888) 752-8994 (TOLL FREE).

I am sending this from my Asus Windows 7 computer because of the problem; this actually occurred on my Windows 8.1 computer but I can't switch to other tabs to send this and am worried about a potential virus.

I'm very concerned about this since I have no prior knowledge that this originates from Mozilla and/or is supported by Mozilla. It looks like just another scam and it won't allow me to close the tab or the message.

I would greatly appreciate help on this. Thanks!!

I launched Firefox and a pop up came saying 'Dear Firefox user congratulations' we thank you for being a loyal firefos user etc... and proposing one year free netflix!!!I tried to close that tab but no ways.. I have had to go to the system monitor in the processes and kill the firefox session.. i attach to this msg screen shots from the issue..