"Microsoft Security Alert", Redirect or "Zeus"

Running Win10 with Firefox Quantum.
Have had several instances with Firefox of blue and (latest) red screens indicating virus and directing to call a Microsoft service number with system being locked up. (NOTE: Interestingly Internet Explorer is NOT compromised and can be used for antivirus efforts?!)
Have used procedures from both and to clear the problem with varying success. I did have some concerns with these sites being legitimate but went ahead since corrective applications were third party, including Malwarebytes which I run regularly.
Is there a good "best source" for a procedure to remove this virus...or, better yet, has Dave come up with one?
Thanks.