Anti-virus Software

macOS has built in security. Using 3rd party antivirus software will not to anything other than slow your system down and cause problems.

There are no known viruses in the wild that can infect macOS. Infecting the current versions of macOS would be almost impossible as the OS resides on a read only partition. Even the local administrator does not have rights to modify it without manually disabling the built in security.

There are no third-party anti-virus apps that should be used on the Mac.

KiltedTim's post above is accurate.

For addition info, please see:

Protecting against malware in macOS - Apple Support

XProtect Explained: How Your Mac’s Built-in Anti-malware Software Works - How-To Geek

macOS security built right in. - Apple 

There has never been, nor will there ever be, a macOS virus.

What has been working for others?

Effective defenses against malware and other threats - Apple Community