IDS: Re: Snort signature packet generator

[Martin Roesch <roesch () sourcefire com>]

There are some tools out there like stick/snot/sneeze that'll do it but  
it's getting harder to make Snort dance like this, especially for TCP  
traffic.  We're doing a lot more protocol analysis these days and most  
of the tcp rules depend on the state of the tcp connection and  
direction of the traffic, so just blasting packets doesn't work so well  
any more .  Your best bet is to stick to  UDP/ICMP attacks.
The absolute best way to get Snort to generate events is to go out and  
grab a bunch of exploits from Packetstorm (or whatever) and run real  
attacks.  It's more work but it'll do the trick.  Alternatively, you  
could go through the Snort rule set and strip out the state management  
checks like the flow and flowbits keywords and run stick/snot/sneeze.   
One other alternative is to grab a big pcap of a hacking event like  
DefCon CTF from someplace and run the traffic back through Snort.
      -Marty


On Nov 5, 2004, at 12:29 PM, Graeme Connell wrote:

> I'm attempting to train a neural network using snort, and I'm having  
> trouble getting a good number of "bad" packets, IE: those that snort  
> considers malicious.  Since a snort signature is really just a  
> definition of a subset of all possible packets, it seems like it  
> should be possible to create a packet that snort considers bad by  
> filling in packet fields based on a snort signature, then filling the  
> rest of the packet with random garbage.  Does anyone know if this type  
> of program has already been created, and if so, where could I find it?  
>  Thanks.
>                 --Graeme Connell
>
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--
Martin Roesch - Founder/CTO, Sourcefire Inc. - +1-410-290-1616
Sourcefire - Discover.  Determine.  Defend.
roesch () sourcefire com - http://www.sourcefire.com
Snort: Open Source Network IDS - http://www.snort.org


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