supposed apple care pop up saying I am infected with 3 viruses.

It's a scam, see > Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support

It's a scam. There are no known viruses for Mac OS.

Force Quit Safari ( command + option + esc keys).Then restart Safari holding the Shift key. 

If you still have problems Empty Caches (Safari menu > Preferences > Privacy > Remove all website data. (This will also remove history if you do not want to remove History open Safari Preferences > Advanced and check mark “Show Develop Menu” then choose “Empty Caches” from Develop Menu ).

Then go to Safari menu > Preferences > Extensions and check there. If there is an extension delete it.

If the problem persists then download and run Malwarebytes. Malwarebytes was developed by one of our own colleagues here in ASC and is about the most proven anti-malware software for Mac.

I see those periodically, and they seem to come in "waves." In my case however, they show up as emails, which are pretty easy to figure out, based on all of the other answers here. Apple doesn't monitor my system (or any system that I know of) to tearhis level of detail, and as others here have noted, websites can't scan the guts your system.

Remember the old adage: if it walks like a duck, and quacks like a duck... Here, a bit of common sense should go a long way. In my case, I don't open anything included in the email, and just delete it. I'd advise the same.

It is a scam since no website can scan the internal

workings of your Mac.

+1

One-hundred percent of these pop-up browser dialogs are not from Apple and are entirely SCAMS.