Re: Obfuscated web pages

I haven't seen any IDS/IPS that do this competently.

ISS's "Proventia" or whatever their new all-in-wonder IPS box is
claims to do this, but then it also lists as a feature that it can
prevent "phishing" so my expectations are rather low.

We have someone deploying it inline for testing so I should
be able to comment more on that device soon, but in general,
even WAFs have a hard time at this.

Doubt this will make this list as last I checked SF still blocks
gmail forwarded email.

Arian J. Evans
software security stuff

On Thu, Feb 14, 2008 at 10:44 AM, Gary Flynn <flynngn@xxxxxxx> wrote:

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




--
Arian Evans
software security stuff

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