[From hata_ph's first link above, my emphasis: [step 4 of 5] Attach this [trojan/virus-infected] file to an email, which prompts the recipient to save and open the attachment. As explained, once it has been saved it will just appear as 'some_text.odt' on the user's desktop. And with the icon we have chosen in the launcher description it will look quite harmless.
Send this email out to as many email addresses as you can get a hold of.
Voila! A Linux virus in 5 simple steps. Every user that saves and opens the attachment you have sent them will get themselves infected with the malware script of your choice, which is then also restarted whenever the user logs in again.
That was easy, wasn't it?
Solutions for the problem
The easiest solution to prevent this kind of problem is to not just blindly click on attachments that people have sent you. [...]
Seem's like the "ease" of getting this kind of virus on a system depends on the user being asleep. Is creating a linux-based virus that doesn't need user interaction much more difficult? If I recall correctly, we've talked about virus infections on *nix before here, but not from this perspective specifically.