On Fri, Jan 23, 2009 at 1:10 PM, David G. Miller <dave at davenjudy.org> wrote: > Stephen John Smoogen <smooge at gmail.com> wrote: > >> On Thu, Jan 22, 2009 at 12:42 PM, David G. Miller <dave at davenjudy.org> wrote: >> >>> > Amos Shapira <amos.shapira at gmail.com> 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. >>>> > <SNIP> >>> > After reading all of the other replies (including the ones that pointed >>> > out that the PCI DSS requirement had changed the terminology from >>> > "virus" to "malware"), why not claim you are meeting the requirement by >>> > doing something useful like running chkrootkit or rkhunter on a regular >>> > basis? That way you would be scanning the systems for the only malware >>> > known to actually pose a threat to a Linux box. It may be a low >>> > probability of infection (as others have pointed out) but should satisfy >>> > the auditor and hopefully will just be a low cost exercise in futility >>> > as long as reasonable security policies are followed. >>> >> >> Any tool will require the need to have a risk assessment against it. >> What is the liklihood of it finding malware? How much is updated and >> how does it compare to other tools. These will be questions that will >> need to be available for auditors to know you did your due-diligence >> on selecting a tool. > Answering those questions would provide the arguments for running a root > kit scanner instead of anti-virus software. That is, the risk of > malware affecting the systems in question is low with near zero > likelihood that a true virus will cause a problem but with the > possibility that a rootkit could compromise the systems. Chkrootkit and > rkhunter are arguably the best tools for finding a root kit. The > programs are updated whenever a new threat is identified. > > Obviously, the OP would need more than my say so as back up for these > assertions. Said back up would also make the case that scanning for > non-existent threats (Linux viruses) would make no sense while scanning > for a real threat makes the most sense. Typically a multi-faceted approach to intrusion detection and prevention will always be more successful and garner the best support. Servers that deal with files, whether file servers or wikis, need anti-virus software. For the best protection a different anti-virus package should be deployed on the client (say clamav on the Linux file servers/wikis, and Sophos on the client PCs). All servers should have monitoring software installed to detect changes to the environment, both for change management auditing and intrusion detection. Having an external system collect the monitoring logs and send alerts is the preferred way as manual collection and monitoring isn't timely enough, nor reliable. A good system monitoring platform like one from SolarWinds would be good here. A change management platform to receive these alerts and match them up against change requests or flag them as unauthorized events should also be in place. A platform such as Numara Footprints or even a help desk system or a bug tracking system on the low end could do this. With those in place you should be in good shape. You should then do routine vulneribility scans, penetration tests and if necessary buy into an intrusion prevention system where it scans the network activity looking for anything out of the ordinary where it can alert you to it, or alert and drop it or whatever you see fit. -Ross