When IDS systems first hit the streets a couple of years ago, I think many were caught up in all the GA-GA bells and whistles marketing hype that accompanied their release. After some time to evaluate the products and adjust our thought processes on how they are implemented, I think we have come full circle on their usefulness and I know we are a lot wiser in our implementation. I for one now tend to back off from allowing a product to automatically modify my configurations in response to something that has the potential to be malicious. Sounds a bit like jumping at shadows. I lean towards manual corrective measures that are a result of some form of human thought process and analysis. Guess I am afraid of AI being introduced at this level. In theory, it sounds like a great idea, but it rarely works out in real life. At least to the degree that would make me comfortable with it. Maybe someday... Too often we look at results, without analyzing the effect that it may have on our ability to operate. Whether your automated IDS response is the result of doing the right thing for the wrong reason, or doing the wrong thing for the right reason really doesn't matter... it is still a mistake that could prove costly in the long run. Right now, I trust a human more than a brick. > -----Original Message----- > From: Robert Graham [SMTP:robert_david_grahamat_private] > Sent: Saturday, February 12, 2000 12:04 PM > To: Kopf , Patrick E.; 'Michael B. Rash'; firewall-wizardsat_private > Subject: RE: Automated IDS response > > For example, if you see somebody pinging your machine looking for > BackOrifice, > nothing happens. Not only can such things be spoofed, but you see a lot of > them > from many hackers. What the hacker is really doing is scanning millions of > machines for BackOrifice. That is likely the only packet you'll ever see > from > the hacker, so it isn't worthwhile destabilizing your firewall blocking > the > person. The average cable-modem user gets 20 non-spoofed scans per day -- > it > really isn't worthwhile reconfiguring the firewall for each one. > > On the other hand, if you machine sees your machine respond to a > BackOrifice > request, then it goes into a tizzy and starts blocking things and giving > higher > priority alerts. > > Robert Graham > CTO/Network ICE > > --- "Kopf , Patrick E." <PEKopfat_private> wrote: > > Network Ice's BlackIce Defender IDS does this type of traffic blocking > > (based on type of attack). Defender only blocks traffic for attacks > that > > are 'non-spoofable'. I don't know if they're the only IDS that does > this or > > not. > > > > Pat Kopf > > > > -----Original Message----- > > From: Michael B. Rash [mailto:mbrat_private] > > Sent: Thursday, February 10, 2000 6:09 PM > > To: firewall-wizardsat_private > > Subject: Automated IDS response > > > > > > > > Having your IDS respond automatically to an IP that is generating > > questionable traffic by dynamically managing your router ACLs (or other > > similar action; tcpwrappers, ipchains, etc...) to deny all traffic from > > the IP can be a risky thing to do from a DoS perspective; nmap's decoy > > option comes to mind. > > > > It would seem that any IDS should only block traffic from an IP > > based on an attack signature that requires bi-directional communication, > > like a CGI exploit over http/80 or something. Are there guidelines for > > deploying IDS response that discusses methods for minimizing false > > positives? Are there any *good* ways of doing this? > > > > --Mike > > http://www.math.umd.edu/~mbr > > > > > > ===== > Robert Graham http://www.robertgraham.com/pubs > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com
This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 14:03:26 PDT