I'm running Arch Linux and using Okular for opening PDF files and FBReader for other ebook formats (Epub, Mobi, etc.). Simply put, here's my question: Assuming some of those documents come from unreliable sources and contain malicious code what can I do to mitigate the risk of compromising the system and opening it for invasion (which can be a common occurrence in this country if you even smell like someone who holds opinions the government disapprove of)?
A few more specific questions:
Is just opening the referred files enough to put my setup at serious risk? The user I use for this is on the sudoers list, so, if compromised, it could be used for escalation.
Suppose I only open the files using a more limited user account, would that at least help?
Outside of setting up a virtual machine only for reading (which wouldn't be practical for a few reasons) or using another computer just for that (same thing), is there anything I can do?