Snort mailing list archives
Re: Writing a "not" snort rule
From: ntbuck12 () yahoo com
Date: Tue, 19 Mar 2013 11:44:26 -0700 (PDT)
Thanks! I hadn't seen that used outside of an IP context. I needed that keyword to find the info I wanted. Thanks! For those interested - The content below is stolen from the snort manual. http://www.snort.org/assets/166/snort_manual.pdf A ! modifier negates the results of the entire content search, modifiers included. For example, if using content:!"A"; within:50;and there are only 5 bytes of payload and there is no ”A” in those 5 bytes, the result will return a match. If there must be 50 bytes for a valid match, use isdataat as a pre-cursor to the content. ________________________________ From: JJC <cummingsj () gmail com> To: ntbuck12 () yahoo com Cc: "snort-users () lists sourceforge net" <snort-users () lists sourceforge net> Sent: Tuesday, March 19, 2013 2:35 PM Subject: Re: [Snort-users] Writing a "not" snort rule He probably gets payed way too much already, this "Joe" character ;-) On a serious note, do a search in the snort_manual for the keyword "negate" and around page 182, and other locations, you will find your solution. JJC On Tue, Mar 19, 2013 at 12:30 PM, <ntbuck12 () yahoo com> wrote:
Attention Joe and snort rule writers. I have read a fair amount of information on writing rules, but now I am stuck on how to to this. How could I detect on the following scenario? - Alert on any packet that contains ANYTHING OTHER THAN "message1", "message2" or "message3", in a certain field. Obviously I could use offset and depth to narrow down to the field I'm looking at, but now to a do a "negative search". Ideas? Side Note: I'm pretty sure whatever Joe Esler gets paid isn't nearly enough. I love the blogs too, Joe. ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_mar _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: https://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://sourceforge.net/mailarchive/forum.php?forum_name=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_mar
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Current thread:
- Writing a "not" snort rule ntbuck12 (Mar 19)
- Re: Writing a "not" snort rule JJC (Mar 19)
- Re: Writing a "not" snort rule ntbuck12 (Mar 19)
- Re: Writing a "not" snort rule JJC (Mar 19)