Hi,
Let me re-approach and introduce myself, Hi I'm a principle security engineer for Fortune 100 companies with 30+ years in the IT industry. I do Social Engineering, Pen-Testing, Malware analysis, Attack Vector Analysis, Security Architecture/Engineering, and Risk and Compliance for a Living. So when I chime in on something related to security, most "C" level company presidents usually listen to what I recommend (CEO, CIO, CFO, Etc,.)...
For those that say AV and Anti Malware is not nessacary on your computers, Mac or Windoze makes no difference, I'm telling you your wrong. If your argument is "It makes my system slow", or "let the other guys cover their own Arse" then not only are you a detriment to society, but also, you are wrong. You are likely also the ones that look at things and say, "well someone else will fix it", or "that's someone else's problem", and walk away, something that has run rampant in our modern society...
Malware and virus propagation are EVERYONE'S PROBLEM. The BlackHat Hackers, Criminal Organizations, and Antagonistic Government Agents are winning, and we ALL have to do what we can to protect ourselves and our neighbors.
So yes, even on a Mac, run a third party AV/Anti-Malware, it may slow your system slightly, but you will be "mostly" protected, and you will both be helping yourself and your network stay a little cleaner. Noting "mostly" is referring to the fact, no one can defend against "zero-days", which in their definition are undetectable initially.
Also, for windows, please for the log of God, go with a third party product! relying on windows defender? You'd be better off uninstalling it as it's giving you a false sense of security. It's been tested as the WORST AV/Anti-Malware available...
Thanks,
Bob Hood