anti virus software

Generally, none; instead, avoid downloading software from sources other than the Mac App Store or the developer websites.

If you accidentally install Mac malware, click here.

If you're concerned about Windows malware, use ClamXav or the tool built into Windows.

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Anti virus is not needed......macOS - Security - Apple

If you happen to ever get Malware use the free version here........https://www.malwarebytes.com

You might also want to take a look at this article:

Effective defenses against malware and ot… - Apple Community

It gives some very good advice for how to protect your Mac.