Firefox is default browser I signed onto two sites, per instructions from a TV video service provider: VidUP and Openload.co Pair. Also, Openload.co Pair is active. Immediately, one of these sites brought up the "Microsoft" warning page, with voice, saying to call a number to resolve the issue or my web pages would be frozen. Pages were frozen for a while. Eventually, Windows Task Manager stopped them. Page came up next time I opened Firefox. "Restart Firefox" crash report. Has happened once before. Netflix account violated. Netflix helped shut down hackers. Video service works through the Internet. MBOX brand, I believe. Please advise.