DBeck said

per se, but now McAfee security software is also popping up on my desktop. I eliminated all of the AMC software residue, and I have blocked pop-ups. I wish I could understand why this all happened coincident with my Firefox upgrade.

Stab in the dark : Did you recently (re)install Adobe Flash Player and forgot to uncheck the optional offer to download McAfee  ?

I did indeed update Adobe Flash Player at the same time I updated Firefox. I did not see that offer/option. So now I am ticked that Adobe did this to me!! Thank you for your insight. I wonder if Adobe could make its link with McAfee more apparent.

You're not the only one who didn't notice the 'bonus' that came along :

https://forums.creativecow.net/thread/378/11692

You might even find a program called 'True Key' : another 'extra' that's often 'offered' when downloading Adobe Flash Player ......

Pretty sneaky  !

Is there a way to get rid of these "bonuses"? I cannot find an "unsubscribe" protocol for McAfee. One would think that McAfee might wish to provide one, because now I am so unhappy with them that I'd never chose them if I were in the market. A new McAfee ad just popped as I was writing this.

DBeck said

Is there a way to get rid of these "bonuses"?

Yes, uncheck the McAfee that's offered (see my screenshot) Personally, since I fell into this trap myself not so long ago : I have set Adobe Flash Player to update automatically and haven't had any such 'surprises' since (knock on wood) .......