Snort mailing list archives
Re: Disable sid vs. Suppress
From: Joel Esler <jesler () sourcefire com>
Date: Thu, 22 Sep 2011 21:00:56 -0400
We have alerts that have flowbit rules that have noalert, we have flowbit rules that don't, and we have some rules that have two variations, one with a flowbit, and one without. For example, we have a rule that looks for the download of a Chrome extension. It sets a flowbit, but it's not a noalert. As the extension is compressed, we are providing the option for Snort I line users to block them completely. If you have a flowbit "set" rule that doesn't have noalert in it, and you don't want the alert, then set a suppression in threshold.conf. -- Joel Esler On Sep 22, 2011, at 12:12 PM, Dave Venman <dvenman () sourcefire com> wrote:
Most VRT rules I see with flowbits from the VRT which do the protocol/state modelling have the "noalert" in the flowbit section, so there should be no need either to modify the rule nor to add a suppression for it either. Of course I'm more than welcome to be corrected . . . On 22 September 2011 17:00, Jefferson, Shawn <Shawn.Jefferson () bcferries com> wrote: Yes, but that entails changing the rule, doesn’t it? (could be wrong) I’d rather not touch the rules as they come from VRT and ET, so I have been using suppression for these. From: Dave Venman [mailto:dvenman () sourcefire com] Sent: Wednesday, September 21, 2011 9:25 PM To: Lay, James Cc: Jefferson, Shawn; snort-users () lists sourceforge net Subject: Re: [Snort-users] Disable sid vs. Suppress Rather than suppression, the "noalert" option in the flowbits portion of the rule can do that for you, i.e. it allows a rule which does detection purely to set a flowbit state (for example the flowbit client_hello in some of the ssl rules, which is used later when the SSL session being inspected is more advanced in its setup ) to *not* generate an event. On 21 September 2011 20:39, Lay, James <james.lay () wincofoods com> wrote: From: Jefferson, Shawn [mailto:Shawn.Jefferson () bcferries com] Sent: Wednesday, September 21, 2011 11:34 AM To: Lay, James; snort-users () lists sourceforge net Subject: RE: Disable sid vs. Suppress Some rules will set flowbits for others rules to fire on, so those ones will have to be suppressed instead of disabled (Pulled Pork nicely re-enables these flowbit setting rules for you.) Thanks Shawn...didn't know that :) James <cut> -- Dave Venman, CISSP Security Engineer Manager, Sourcefire EMEA Email: dave.venman () sourcefire com Mobile: +44 (7917) 168068 DDI: +44 (118) 989 8412 Fax: +44 (118) 989 8401 ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ 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://www.geocrawler.com/redir-sf.php3?list=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
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_______________________________________________ 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://www.geocrawler.com/redir-sf.php3?list=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
Current thread:
- Disable sid vs. Suppress Lay, James (Sep 21)
- Re: Disable sid vs. Suppress Alex Kirk (Sep 21)
- Re: Disable sid vs. Suppress Lay, James (Sep 21)
- Re: Disable sid vs. Suppress Jefferson, Shawn (Sep 21)
- Re: Disable sid vs. Suppress Lay, James (Sep 21)
- Re: Disable sid vs. Suppress Dave Venman (Sep 21)
- Re: Disable sid vs. Suppress Jefferson, Shawn (Sep 22)
- Re: Disable sid vs. Suppress Dave Venman (Sep 22)
- Re: Disable sid vs. Suppress Joel Esler (Sep 22)
- Re: Disable sid vs. Suppress Lay, James (Sep 21)
- Re: Disable sid vs. Suppress Alex Kirk (Sep 21)