I downloaded a virus under the Microsoft auto update popup

Follow advise of previous posting First.

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX  Foundation and Permission Limitation. 

The The Built in Security  is all that is required to protect the computer.

Should “ Certain & Specific Software “ referenced from above be installed - it will negatively impact macOS. It is suggested, to download directly from a respected ASC Contributor, the application Malwarebytes for Mac. 

It is free or paid for added features. 

Run the Application and it should remove the malware / adware. Once done, restart computer and test.

Tell my how you managed to do that, and maybe I can figure out how to fix your problem.

If you can download an run EtreCheck, use Share Report > Copy Report and paste into the Additional Text area, here (document icon).