I don't think it was a Microsoft critical link but malware. Have a look in ad-ons and extentions, in Firefox, and disable or uninstall anything you don't recognise. Re-set your home page. Check programs and features for an unknown program and uninstall. Run Ccleaner's reg cleaner. Finally run Malwarebytes in safe mode then normal mode.
UK's best mobile network 2016: best 3G, best 4G, best mobile networks revealed