Linux Virii

question;
how is linux affected by virii, and how does it combat them?

STOP RUNNING AS ROOT, DUMBASS!  I personally learned that lesson a few years ago, running xchat or something IRC as root, bragging about getting Linux working, and getting rooted five minutes later.  Luckily, he wasn't an ass, and didn't trash anything, so I was able to unplug the ethernet and reinstall.

Linux is definately not immune to specific attacks, but virii aren't going to be a problem, possibly ever, at least on a gigantic scale.  If a major hole in the Linux plan is exploited, you can bet it'll be fixed quick.  Unlike Windows, where nobody'll let you fix it and you have to rely on third party crap.