RE: Obfuscated web pages

["Mike Barkett" <mbarkett () us checkpoint com>]

You're really talking about the difference between client-based protections
and server-based protections.  Let's not throw the baby out with the
bathwater; network IDS/IPS does much more than just "AV style malware
signatures for malicious web server issues."  Most of today's IPS products
can quite deftly clean out a vast array of types of malicious activity,
whether automated or not, across a bevy of network protocols, not just web.

Regarding inline JS inspection, I've said it before and I still believe that
one day there will be a full DOM proxy product that is capable of running
inline.  Yes, its speeds will lag other network devices, and yes, browser
attacks will probably be yesterday's news by then anyway, but it would be
foolish to suggest that it is theoretically impossible to do.  In the
meantime, if you have embraced defense-in-depth and gotten yourself a
trustworthy network IPS, a thorough endpoint solution, and you use only
locked down browsers, then you'll be ok.

-MAB


--
Michael A Barkett, CISSP
IPS Security Engineering Director
Check Point Software Technologies
+1.240.632.9000 Fax: +1.240.747.3512

> -----Original Message-----
>
>
> Are any current network based IDS/P systems able to unwind
> obfuscated web script to examine the final javascript product?
> It would seem they would have to have a javascript engine to
> do so and issues with reassembly, iterations, and delays
> would preclude them from doing it inline.
>
> Without this capability, it would seem that network based
> IDS/IPS is destined to digress to AV style malware
> signatures for malicious web server issues and that the only
> reliable place to do IDS/P would be on the host.
>
> We've been seeing more and more obfuscated web script and
> according to a recently released IBM report, the majority
> of exploits are taking this path.
>
> http://www.iss.net/x-force_report_images/2008/index.html
>
> Thoughts?
>
> --
> Gary Flynn
> Security Engineer
> James Madison University
> www.jmu.edu/computing/security


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