I posted this on the wrong forum and am reposting here.
I update two mirror image backups of my Mac Pro (early 2008 running El Capitan) boot drive every night. When I check the Virus Chest in the mornings, it always has files there, and there are always two copies of each file, one from each of the two backup drives. There are none from my boot drive. If they are on the backups, they must be on my boot drive. Why isn't Avast finding them?
They are always from my Apple Mail attachments folder, so I'm sure they're coming from spam. I just delete them from the Chest