Good, free Antivirus for Macs?

I'm main computer supporter for my octogenarian parents. My dad has a Macintosh laptop and asked me about a popup from Macafee antivirus claiming the laptop is infected. Oh, and it says he needs to upgrade to remove the infection. He don't recall ever installing Macafee and is doubtful about the infection, yet don't want to do banking or payment online until it is dealt with.

I haven't used Macs for ages so don't quite know where to start. Googling tells me there's an inbuilt antivirus/antimalware program called Xprotect. If I check that it is activated and it hasn't detected any malware, is he good to go?

Is there another good, free antivirus for Macs out there?

via International Skeptics Forum https://ift.tt/uwMsbP4