Ask HN: Do you use anti-virus software?

Windows Defender.

If I download a sketchy binary, I'll run it through VirusTotal, but there's no reason to have any of that junk running on my PC all the time.

Yes, can’t have some zero days on my computers. I use anti-virus, virustotal and yara on top (see my tutorial https://youtu.be/Le6sZRV6Rwc)

Whenever I'm on windows I "use" defender (on by default).

Otherwise I just run stuff through Virustotal.

Windows Defender, that's all you need.