Snort mailing list archives
Re: Question regarding a rule
From: James Lay <jlay () slave-tothe-box net>
Date: Tue, 24 Jun 2014 12:03:41 -0600
On 2014-06-24 12:00, Charlie Egan wrote:
Cheers for both of your replies. I tried adding the to_server bit funnily enough just before you wrote that email, still no luck unfortunately. Ive tried adding the detection filter on as well, still no luck with that either! The alerts are still piling through a few minutes after, over the period of about three seconds. As well as the time delay, Im confused as to why there are so many alerts. Apologies, didnt mean to email you back directly James. Cheers On Tue, Jun 24, 2014 at 6:39 PM, James Lay <jlay () slave-tothe-box net [12]> wrote:On 2014-06-24 11:26, Y M wrote:Ok, GUI is out of the way. I am just guessing here, but since there is no flow direction intherule; only "established" without a flow direction (to_server, from_client, etc...) Snort will alert after it flushes the tcp sessions, I am almost sure that I read this somewhere. If youuse,for example, to_server, Snort would alert as soon as the contentmatchesand knows that it was you (the client) who established/initiatedtheconnection (through stream5) and alert based on that. However, I stand corrected on all of the above. If you add the flow direction to your rule, does that change the alerting behavior? -------------------------Date: Tue, 24 Jun 2014 18:09:05 +0100 Subject: Re: [Snort-sigs] Question regarding a rule From: chas5873 () gmail com [1] To: snort () outlook com [2] CC: snort-sigs () lists sourceforge net [3] Cheers for the reply mate. Im not using a GUI, just running it in through a terminal. Itstheonly rule which its happening with so far, confusing me to saytheleast!On Tue, Jun 24, 2014 at 6:06 PM, Y M <snort () outlook com [4] [8]>wrote:Are you using a GUI or just running in console mode to view the alerts? "Usually", in a GUI scenario, alerts are cached and depending in refresh rates the alerts will show up. Does thishappenonly for this rule or others as well? -------------------------Date: Tue, 24 Jun 2014 17:17:09 +0100 From: chas5873 () gmail com [5] [1] To: snort-sigs () lists sourceforge net [6] [2]Subject: [Snort-sigs] Question regarding a rule Hi guys, Im having a bit of trouble with a rule that Im playing aroundwithto detect torrent usage. alert tcp any any -> any any (msg: "P2P torrent metafiledownload";content:"|38 64 61|"; flow:established;classtype:policy-violation;sid:1000001; rev:1;) After examining the hex dumps from multiple torrents, I noticedthatthey all begin with 38 64 61, so thats where I managed to getthatcontent from. When I run Snort and download the torrent though, it doesntalertme straight away, however gives me about 20 alerts about 3 - 4 minutes later. Does anyone have any idea what could be causing this? Cheers, CharlieAlso try detection_filtering your sid for testing: alert tcp any any -> any any (msg:"P2P torrent metafile download"; content:"|38 64 61|"; flow:established; classtype:policy-violation; detection_filter: track by_dst, count 1, seconds 60; sid:1000001; rev:1;) Ive seen cases where if too many alerts fire on the same content they wont all show up at the same time. James
No sweat..that happens. I'm assuming that you killall -HUP snort to get the new rule with the detection filter yes? How many alerts did you see in a minute? James ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Snort-sigs mailing list Snort-sigs () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-sigs http://www.snort.org Please visit http://blog.snort.org for the latest news about Snort!
Current thread:
- Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule Y M (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule Y M (Jun 24)
- Re: Question regarding a rule James Lay (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule James Lay (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule James Lay (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule Y M (Jun 24)
- Re: Question regarding a rule Y M (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule rmkml (Jun 24)
- Re: Question regarding a rule Charlie Egan (Jun 24)
- Re: Question regarding a rule James Lay (Jun 25)
- Re: Question regarding a rule Charlie Egan (Jun 25)
- Re: Question regarding a rule James Lay (Jun 25)