Just FYI to users of Avast free anti-virus for Mac, a number of users, myself included, who use the Avast anti-virus for Mac have found that Avast has surreptitiously installed something called SecureLine VPN on our machines. There are discussions on the Avast online forums (see https://forum.avast.com/index.php?topic=172391.0 and https://forum.avast.com/index.php?topic=172142.0 for example).
Don
Don