I'm using Linux Mint 17.3, is there any antivirus that is good for it?
Zevon: Yes, get clamav.
You install it just like you install everything else on Linux, though the Package Manager
1. Go to Administration/Synaptic Package Manager
2. Search on "clamav"
3. Tick the box and click Apply.
It will haul in all the parts automatically, and set up an auto update of the virus database.
Note that Linux does not really need antivirus for itself – what clamav does is to catch any Windows viruses that come past, and prevent you from infecting your friends with them.
There are AV programs for it, but there are very, very few bits of malware that even work on Linux. Linux doesn't allow the kind of access to the system that Mac OS and Windows do; it has all root access disabled by default.
Read the Ubuntu wiki in the source, the comments apply to other variants of Linux.
AVG works good