[Bro] grp ports variable and dpd on bro not work ?

Robin Sommer robin at icir.org
Fri Feb 29 08:52:58 PST 2008

On Wed, Feb 27, 2008 at 10:46 +0100, you wrote:

> 1) It is possible detect GOBBLES alert without fix tcp port ? (and use dpd)

This works fine for me:

> cat test.sig 
signature sid-1812 {
  ip-proto == tcp
  event "EXPLOIT gobbles SSH exploit attempt"
  tcp-state established,originator
  payload /.*GOBBLES/
> bro -C -r exploit_sshgobbles22000.pcap -s ./test.sig -f tcp tcp signatures dpd
1204117394.397943 SensitiveSignature EXPLOIT gobbles SSH exploit attempt

How does your mt.bro look?

> 2) if I replace 'payload /.*GOBBLES/' to 'ssh /.*GOBBLES/', bro stop and alert: parse error  (on this line)
>  -> maybe in next bro releases ? (like http payload)

What exactly do you want the "ssh" to keyword to do? As most of a
ssh session in encrypted, it could match only on the first--which is
just what payload is doing as well (note that Bro stops processing
SSH content after the first line, i.e., payload is not doing any
further matching).


Robin Sommer * Phone +1 (510) 931-5555 * robin at icir.org 
ICSI/LBNL    * Fax   +1 (510) 666-2956 *   www.icir.org

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