Removal of nonspewpa.com

As careful as I am, somehow I got infected with nonspewpa.com. Now about every 60 seconds I get a popup from them wanting me to buy McAfee (I know this is a scam.)

I'm curious why Bitdefender/Armor did not catch this and when I did a scan, it was not found for removal.

Any suggestions on how to get this cleared up?

Answers