I was put onto Avast by Kim Komando.com ten years ago. That may be one reason I've kept this MS Millennium running fine for ten years!
Brief and costly diversions to Norton and McAfee cost me many hours of fixing their errors.
One problem, at least with dial-up, is a long5-10 minutedaily downloading. (Which I tolerate, given the alternatives). Spybot and Ad-Aware, also free, help.
Based on a little Googling, I think Avast is based outside the US.
“Based on a little Googling, I think Avast is based outside the US.”
Avast is a Czech company.