Then again, you don't need a huge vulnerability, you just need enough hapless users who voluntarily download and install software containing your malware...
So don't give them root access, and mount the /home partition as noexec to prevent executing downloaded programs.
I set up a dual-boot Ubuntu install many years ago like this. It worked for years without me realizing — the Windows install had some problem, and my dad started using Ubuntu without telling me.
It's still pretty easy to download malicious shell scripts that can wreck your user data and configs on Linux, so noexec is a great tip for setting up a system for a non-technical user.
