Re: Snort + sfPortscan + Barnyard2

[Antonio Piepoli <piepoli.antonio () gmail com>]

Yes that thread is a bit out of date. I've also searched - a bit- on the
archives of this mailing list but without success.

Maybe it's true that is hard to tune the preprocessor but I did not notice
that was so hungry of resources.


2014-03-11 19:44 GMT+01:00 Maxwell, Jamison [HDS] <JMaxwell () pbp1 com>:

> I found this on the snort google group
> https://groups.google.com/forum/#!topic/mailing.unix.snort/TgJbigmGpSQ .
>
>
>
> It basically says that the BY2 guys are working on a solution for
> databasing these logs, but that was two years ago.  Maybe some of the
> Barnyard2 folks can comment?
>
>
>
> To be honest, I’ve never played with this preprocessor until now, I don’t
> really care who scans, to be honest, but in turning it on I’ve noticed that
> it’s chock full of false positives, even at the lowest alerting threshold,
> and has increased my load by about thirty percent, and memory usage through
> the roof.  Seriously, it ate my swapfile.  I don’t think I’ll be using this
> preprocessor much.
>
>
>
>
>
> Jamison Maxwell
>
>
>
> *From:* Antonio Piepoli [mailto:piepoli.antonio () gmail com]
> *Sent:* Tuesday, March 11, 2014 1:12 PM
>
> *To:* Maxwell, Jamison [HDS]; snort-users () lists sourceforge net
> *Subject:* Re: Snort + sfPortscan + Barnyard2
>
>
>
> Thank you,
>
> I've already read that part of documentation and I'm glad to see that I'm
> not the only one who thinks it is a bit obscure :) .
>
> Hope someone can help.
>
> Antonio
>
> Il 11/03/2014 17:24, Maxwell, Jamison [HDS] ha scritto:
>
> Yes, Barnyard2 only processes unified2 format files, but you should be
> able to change  the output to unified in snort.conf.  I’m not sure quite
> how though, as I’ve never really monkeyed to much with separate
> preprocessor logs, but it looks like there’s some info about it starting on
> line 213 in doc/README.sfportscan.
>
>
>
> *(unified)*
>
>
>
> *In order to get all the portscan information logged with the alert, snort*
>
> *generates a pseudo-packet and uses the payload portion to store the
> additional*
>
> *portscan information of priority count, connection count, IP count, port
> count,*
>
> *IP range, and port range.  The characteristics of the packet are:*
>
>
>
> *Src/Dst MAC Addr == MACDAD*
>
> *IP Protocol == 255*
>
> *IP TTL == 0*
>
>
>
> *Other than that, the packet looks like the IP portion of the packet that
> caused*
>
> *the portscan alert to be generated.  This includes any IP options, etc.
> The*
>
> *payload and payload size of the packet is equal to the length of the
> additional*
>
> *portscan information that is logged.  The size tends to be around 100 -
> 200*
>
> *bytes.*
>
>
>
> *Open port alerts differ from the other portscan alerts, because open port
> alerts*
>
> *utilize the tagged packet output system.  This means that if an output
> system*
>
> *that doesn't print tagged packets is used, then the user won't see open
> port*
>
> *alerts.  The open port information is stored in the IP payload and*
>
> *contains the port that is open.*
>
>
>
> *The sfPortscan alert output was designed to work with unified packet
> logging, so*
>
> *it is possible to extend favorite snort GUIs to display portscan alerts
> and the*
>
> *additional information in the IP payload using the above packet
> characteristics.*
>
>
>
> Though, I’m don’t think this information is very clear.  Also, you’re
> specifying merged.log in your -f option, which is processing
> /var/log/snort/merged.log, not portscan.log, but it would need to be
> unified anyway.
>
>
>
>
>
>
>
> Jamison Maxwell
>
>
>
>
> *From:* Antonio Piepoli [mailto:piepoli.antonio () gmail com<piepoli.antonio () gmail com>]
>
> *Sent:* Tuesday, March 11, 2014 12:12 PM
> *To:* Maxwell, Jamison [HDS]; snort-users () lists sourceforge net
> *Subject:* Re: Snort + sfPortscan + Barnyard2
>
>
>
> First of all thank you for the assistance,
>
> I'm running barnyard with this command:
>
> */usr/local/bin/barnyard2 -c /usr/local/etc/barnyard2.conf -d
> /var/log/snort -f merged.log -D*
>
> In the config file of barnyard it's written nowhere to process
> portscan.log (I knew it was trivial).
>
> Actually I think I'm missing something. The file portscan.log is written
> in cleartext while merged.log is unified2, is it not mandatory for barnyard
> to read files in unified2 file format? Does snort have to update *merged.log
> *to include sfportscan's alerts?
>
>
> Thanks,
> Antonio
>
> Il 11/03/2014 16:55, Maxwell, Jamison [HDS] ha scritto:
>
> The first thing I would do is ensure that portscan.log is being processed by barnyard2.  You should see this in 
> /var/log/messages, but you can also turn on mysql logging and watch the INSERT queries.  In my configuration, on 
> RHEL, the config file you specify the lag to parse is /etc/sysconfig/barnyard2.
>
>
>
>
>
>
>
>
>
> Jamison Maxwell
>
> Sr. Systems Administrator
>
>
>
> -----Original Message-----
>
> From: snort-users-request () lists sourceforge net [mailto:snort-users-request () lists sourceforge net 
> <snort-users-request () lists sourceforge net>]
>
> Sent: Tuesday, March 11, 2014 10:34 AM
>
> To: snort-users () lists sourceforge net
>
> Subject: Snort-users Digest, Vol 94, Issue 24
>
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-- 
Antonio Piepoli

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