For ages it was safe to download and open random files on Linux, because they simply would not run. Now Linux is a very desirable target for criminals, so they learned to write multiplatform viruses.

The best option would be an automatic sandbox for running random crap downloaded who knows where, and Android does that automatically, but on desktop Linux you need to either create a new user (and remove world-readable permissions from your main account files), or create a custom Docker container, or create a chroot, or launch a VM, all of which require half a day of learning new tools, and then debugging why graphics would not work.