My bank info was stolen and I don’t yet know how. I scanned my mac with avast and it says everything is OK. Does Avast find keyloggers in case this is the issue? I am running macOS 10.12.5 and Avast 12.7
Ofcourse avast (along many other things) can find many keyloggers.
You are assuming it was malware on the machine that compromised the account, which isn’t always the case.
Lately, attackers have been compromising account databases at websites and using them to attack other sites like banks, since many people reuse their passwords.