[all variants] How to scan downloaded files for Linux malware?

I've been using ClamAV (with added anti-hackingteam and LinuxMalwareDetect databases) to scan downloaded files for Linux malware and Windows malware... or so I thought, until I read this post by DuckHook. I do most of what DuckHook suggests and some other things too (like sandboxing and VMs), but still that is pretty conceing - for personal reasons, I can't ever 100% trust my common sense. So I've been trying to use anti-malware scaer as a "second opinion", not a perfect indicator of whether something is malware or not.

Yes I know people say malware scaer is not needed on Linux because if I don't stupidly type in my sudo password it can't infect the whole system. But I don't want my home directory infected either.

So how to set up ClamAV to scan downloaded files for Linux malware?