Malicious McAfee pop-ups.

I keep getting McAfee pop-up notifications for renewing or turning on McAfee apps.

I don't use McAfee, so I assume these are entries for malware. How do I get rid of these pop-up notifications?

I use an iMac Retina 5K, 27-inch, Late 2015 with 4 GHz Quad-Core Intel Core i7 and OS 12.6.8.