My first book was on fighting computer viruses, but that was 25 years ago. 25 Years! Where does the time go? I remember Symantec sent me a Virus Zoo. I actually had the top 100 or so viruses on floppies that I used to infect my test computer and get screen shots. I used a bit editor to look around in the within the virus' code. I still remember how cool it was to read "Frodo Lives" hidden inside a virus.
I'm no longer anywhere near an expert in malware, but I did write a book on the subject in it's infant days. So maybe you're wondering, what do I use today to keep my computer safe? (besides not clicking on phishing, not going to weird websites, etc)
And yes, even on a Mac, I run security software.
My favorite security software product is ESET. I've trusted them for over a decade. I first learned about ESET from my fellow Microsoft MVPs. One of their researchers is an MVP and most the MVPs used ESET NOD32. It usually ranks at or near the top of actual virus tests, does a great job of catching new viruses in the wild, and it has extremely low CPU and memory footprint.