I am not sure I agree with this but will pass the information along in case it works for someone else. (I use Macintosh and Chromebook computers so viruses aren’t much of a concern for me. I cannot verify this article about Windows viruses.)
Former Firefox developer Robert O’Callahan claims, “antivirus software vendors are terrible; don’t buy antivirus software, and uininstall it if you already have it (except, on Windows, for Microsoft’s).”
He also claims, “Perhaps it should go without saying — but you also need to your OS to be up-to-date. If you’re on Windows 7 or, God forbid, Windows XP, third party Antivirus software might make you slightly less doomed.”
O’Callahan then provides justification for his claims in his article at: https://goo.gl/74Js0l.