There is an issue where there's something opening up a new tab, McAfee saying it needs to scan for viruses.
I had it around late September or October. There was another user who did though I forget who. And recently Doggo_Gal did
Though they did say it also happened when they weren't on WP, it still might very well be stemming from here. I haven't had any issue like this before until I was going on WP
And McAfee is aware of these fake pop-ups, as far as I could find, and have warn against them.
So basically, what this does is randomly open up a new tab on its own and says your device needs to be scanned. And from the stuff I could find, correlating with what Doggo said, if you decide to scan it, it will say it found 5 viruses.
The best I can find to combat this was to of course X out, and then reset your browser. Like, clean the cache and such. I forget how to do that though, last time I did it also removed all my YouTube recs so I'm no expert.
So if you get a McAfee pop-up, whether you actually have McAfee or not, do not fall for it. It is a virus, a scam. Not the real McAfee, and they're aware of the fake stuff.
I did post this in my news book as well, but the entirety of WP isn't all looking at that book so this makes it easier to warn about.