I keep getting a notification that my Mac has been infected with a virus

If these are sliding in the from the top right of the screen, a site you visited has given itself permission to send push notifications. Everything you're seeing is nothing but a scam. You aren't infected with anything.

Open Safari's preferences. Click on the Websites tab and then scroll down to Notifications. Clear any entries in the right hand window. You might find something similar in the Pop-up Windows heading below that. Block any you don't recognize.

Then if you want, uncheck the box below as shown here.

I personally can't think of any reason why I would ever want any website to push notices to me.

Learn how to block annoying pop-up ads in Safari on your iPhone, iPad, iPod touch, or Mac using the tips in this support article --> Block pop-up ads and windows in Safari - Apple Support

Scams (e-mail, text messages, and phone calls) are getting very good at closely imitating true Apple communications. Always be cautious. These support articles have some guidelines:

About identifying legitimate emails from the App Store and iTunes Store --> Identify legitimate emails from the App Store or iTunes Store - Apple Support

Recognize and avoid phishing messages, phony support calls, and other scams - Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

Avoid scams when you use Apple Cash --> Avoid scams when you use Apple Cash - Apple Support

Apple 'How to identify, avoid, and report phishing' video--> https://youtu.be/SR3Z3fXXjfw

If you are uncertain about a message and a resource provided in that message, do not click on any links in the message. Try to independently verify the resource by going to a support page on apple.com and use that to contact Apple or to verify with the service the message is telling you to use.

I mean an anti virus / malware software that actually works on a Mac - Mac is generally pretty good but this is annoying as F*

If by "actually works" you mean, "makes Mac run poorly, reduces security, and doesn't do anything about malware," they all "actually work" quite well.

If you allowed notifications from websites or installed Adware, you should disable/remove them.

You're welcome. 🙂

while it is troublesome and quite annoying, I am glad I was not alone w/the ”virus” notification others got also. THANKS TO ALL WHO replied to me, and others w/the same problem. The funny thing about it for me, is that I do frequently check to make sure there are no websites that I have not actually gone to, and I am forever blocking ads, managing what ads I might be interested in.. not tech savvy at all but for some reason those seemed to be things to check frequently. I was also getting an email that my iCloud was full. I have never opened iCloud.. have no interest in storing thing somewhere out there in never never land. Rest assured you have helped calm me down.

is there such a thing as really good virus alert for Macs?

If by "really good" you mean exceptionally funny, there are a few.

Thanks for that info

Just what I needed to fix mine. Worked like a charm. Thank you.

You are a life saver. 💯 thank you a million & 1 times. 🫶🏽