[Snort-devel] Fwd: Re: Fwd: Re: Snort Anomaly Detection

Bernhard Guillon Bernhard.Guillon at ...3094...
Mon Sep 20 18:48:36 EDT 2010


On 20.09.2010 03:09, Andres Carrera Rivera wrote:
> Yes I try it your configuration (your snort.conf)
> and I got the same Output that you, with the same number of alerts, I 
> attached it.
>

Ok, thanks!

> Also there's my snort.conf.
> I use almost every preprocessor, and use the snort rules, that I 
> downloaded from snort.org/rules
> but for a reason I don't know, my snort.conf doesn't show the same 
> alerts like yours (The PHAD alerts).
>
>

I never tried my preprocessor in conjunction with other preprocessors 
because I only wanted to use anomaly detection algorithms. As far as I 
know snort rules and preprocessors are able to alter the packages. 
Because I do not have the snort rules right now (need to create an 
account first) I just tried without the rules (here is my config [1]) 
and I got a lot of spp_phad alerts. But most of the output [2] is bogus. 
I need to find out why. I believe that the way I "misused" the output 
system (see patch [3] ~line 819-849) to support non const char might be 
insane and led to the bogus output. Otherwise the most weird part 
"Preprocessor: PHAD Training ends" is const and called before (see patch 
[3] ~line 407) the non const part.

I need to read more documentation and source of the other preprocessors 
to know what they are doing and if they might influence the output as 
well. I truly would like to spend more time to get it fixed quickly but 
I currently have no time to do that. I have to get some paid work done 
first. And after that the next semester begins which is on a higher 
priority than my free time stuff ;)

To cut a long story short I don't know if I find time to fix it. Don't 
bet on it - sorry.

Best regards
Bernhard Guillon

1 http://student.cosy.sbg.ac.at/~bguillon/snort.with.some.preprocessors.conf
2 http://student.cosy.sbg.ac.at/~bguillon/snort.bogus.output.txt
3 http://student.cosy.sbg.ac.at/~bguillon/snort-2.8.6-spp_phad.diff





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