Linux

I don't, but that's because of how I have things setup around the network. While most people here say it's because they don't need it, I am in a position that I need SOMETHING simply because others in the household could bring in malware and rather than trust them to make smart decisions, I proactively monitor all network activity for anything unusual. That being said, I have clamAv installed and run a weekly scan, but my real "antivirus solutions" are as follows: A syslog server that's connected to grafana/MySQL and alerts me based on very specific criteria. Along this, I've got my network firewall configured to block all "untrustworthy countries" in and out 100%, as well as use an IDS/IPS (also connected to syslog for alerts). Lastly, an internal DNS which grabs from like 20 sources that include some reliable lists with malware domains and such, and a custom list of my own that I add to as useful security news feeds hit my RSS feed with urls in their blog posts.

Actually got a list of other things going on in the network to make it even more secure, but just wanted to list the main things that'll give you a step up in the anti-malware front.

None of this is buletproof without proper care for how you use the Internet, though.

• Check for router/modem/firewall updates weekly if they can't be auto updated
• never click any links in an email even if you feel you know you trust it (exception to this would be something you KNOW is coming into your inbox, such as an account registration verification)
• avoid tiny urls or suspicious looking urls when possible
• don't open ports unless you really really really know what you're doing. If you absolutely need to open a port, then for the love of god define the source IP address/CIDR. Opening ports to the world includes opening them to cyber criminals
• turn off upnp, I don't care what that game or service you use says, it doesn't need it

You get the idea. My message got way too long and turned into a rant lol.