Re: ssh and ids

[Martin Roesch <roesch () sourcefire com>]

Hey Mark,

VENDOR ALERT: I'm a vendor and I'm going to talk about my technology.   
Please take my comments with an appropriate amount of sodium chloride.

Sourcefire's RNA product is capable of isolating/identifying layer-7  
protocols (including encrypted protocols) and tracking the flows.  For  
example, if you wanted to find SSH/SSL traffic that it being initiated  
from outside your network to inside, setting up a query (or automated  
reporting) is pretty trivial.  Hacker busts into your network and sets  
up an SSH server, RNA picks it up and can let you know that it detected  
a new service and logs the flow data, etc.  Anyway, if you're  
interested in seeing a demo or talking more, let me know.

As far as IDS being able to do much with encrypted traffic, there's  
generally not much to do once the session goes encrypted.  You can  
setup rules in a system like Snort to differentiate between "allowed"  
and "everyone else" hosts talking to machines on your network pretty  
easily (and you can query RNA's flow data for the info too).

I know the NAI guys just released a mod to their sensors that allow  
them to do real-time SSL decryption if you're willing to escrow the  
private crypto keys on the box (shudder).  There's been talk of  
implementing the same sort of thing in Snort (ala ssldump) for a while,  
but it's never come together...

      -Marty


On Jun 18, 2004, at 2:18 PM, Runion Mark A FGA DOIM WEBMASTER(ctr)  
wrote:

> Lets suppose the attacker is mildly sophisticated, and after making the
> initial assault roots the box and installs a secure backdoor or two.   
> Is
> there any IDS capable of isolating data it cannot read, except to  
> monitor
> authorized port usage of a system or group of systems?  Not to  
> complicate
> the question, but when the attacker is using portal gates and all
> communications traffic is encrypted in normal channels how can an IDS
> participate?  Monitoring normal traffic patterns seems a bit slow for
> detection.
>
> -
> Mark Runion
>
>
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--
Martin Roesch - Founder/CTO, Sourcefire Inc. - (410)290-1616
Sourcefire: Intelligent Security Monitoring
roesch () sourcefire com - http://www.sourcefire.com
Snort: Open Source Network IDS - http://www.snort.org


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