On Thu, Jan 22, 2009 at 12:19:27PM +1100, Amos Shapira wrote:
Hi All,
Yes, I know, it's really really embarrassing to have to ask but I'm being pushed to the wall with PCI DSS Compliance procedure (http://en.wikipedia.org/wiki/PCI_DSS) and have to either justify why we don't need to install an anti-virus or find an anti-virus to run on our CentOS 5 servers.
Whatever I do - it needs to be convincing enough to make the PCI compliance guy tick the box.
So:
- Has anyone here gone though such a procedure and got good arguments
against the need for anti-virus?
Amos - the best argument I have ever seen along those lines is here : (And its a good one )
http://linuxmafia.com/~rick/faq/index.php?page=virus
All UNIX/Linux aficionados should be familiar with its content.
FAIR WARNING, It is long and complex. Because it is comprehensive and detailed. Those among you familiar with Rick Moen will understand and appreciate why.
A portion pasted here:
The most recent version of these essays can be found at http://linuxmafia.com/~rick/faq/. Rick's Rants
Virus . . . o Should I get anti-virus software for my Linux box? o But didn't security expert Simson Garfinkel say that all Linux systems need virus checkers? o Don't the rise of Linux worms show that Linux now has a virus problem? o Isn't Microsoft Corporation's market dominance, making Linux an insignificant target, the only reason it doesn't have a virus problem? o But how can you say there's no virus problem, when there have been several dozen Linux viruses?
Should I get anti-virus software for my Linux box?
The problem with answering this question is that those asking it know only OSes where viruses, trojan-horse programs, worms, nasty Javascripts, ActiveX controls with destructive payloads, and ordinary misbehaved applications are a constant threat to their computing. Therefore, they refuse to believe Linux could be different, no matter what they hear.
And yet it is.
Here's the short version of the answer: No. If you simply never run untrusted executables while logged in as the root user (or equivalent), all the "virus checkers" in the world will be at best superfluous; at worst, downright harmful. "Hostile" executables (including viruses) are almost unfindable in the Linux world — and no real threat to it — because they lack root-user authority, and because Linux admins are seldom stupid enough to run untrusted executables as root, and because Linux users' sources for privileged executables enjoy paranoid-grade scrutiny (such that any unauthorised changes would be detected and remedied).
Here's the long version: Still no. Any program on a Linux box, viruses included, can only do what the user who ran it can do. Real users aren't allowed to hurt the system (only the root user can), so neither can programs they run.
Because of the distinction between privileged (root-run) processes and user-owned processes, a "hostile" executable that a non-root user receives (or creates) and then executes (runs) cannot "infect" or otherwise manipulate the system as a whole. Just as you can delete only your own files (i.e., those you have "write" permission to), executables you run cannot affect other users' (or root's) files. Therefore, although you can create (or retrieve), and then run, a virus, worm, trojan horse, etc., it can't do much. Unless you do so as "root". Which it's simple to avoid doing.
==============================================================
This is just the beginning - it continues on to cover every aspect of the issue in a mere 1100 lines....
All of it well worth reading.
Jeff Kinz.