Snort mailing list archives
Re: Alert on contents of proxy traffic
From: "Gould, Scott" <scott.gould () gogstats org>
Date: Mon, 26 Nov 2007 11:47:18 -0500
Thanks for the prompt reply Snort version 2.4.5 Proxy runs on port 80 An example rule would be just about any web content. For example, a rule that triggers on the outside between the internal proxy server and external webservers with the following options: alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"Test Phrase"; content:"test Phrase"; nocase; flow:to_client,established;........... Would only trigger on the inside between the internal client and internal http proxy server, if I remove the flow info: alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"Test Phrase"; content:"test Phrase"; nocase; ...................................... For testing purposes I have set the $EXTERNAL_NET and $HOME_NET to any. BTW, there are 2 different snort instances here. But, other than server specific settings for some of the preprocessors (servers which are not involved in this scenario), the configs are the same for testing purposes. Scott -----Original Message----- From: rmkml [mailto:rmkml () free fr] Sent: Monday, November 26, 2007 9:00 AM To: Gould, Scott Cc: rmkml () free fr Subject: Re: [Snort-users] Alert on contents of proxy traffic Hi Scott, what snort version you use please ? maybe send example (traffic/alert) ? and send snort.conf ? what port on your proxy please ? (81 ? 3128 ? 8000 ? 8080 ?) Interesting think with snort 280 and port var features ! Best Regards Rmkml On Mon, 26 Nov 2007, Gould, Scott wrote:
Date: Mon, 26 Nov 2007 11:29:31 -0500 From: "Gould, Scott" <scott.gould () gogstats org> To: Snort-users () lists sourceforge net Subject: [Snort-users] Alert on contents of proxy traffic Here is the setup: Snort listening on traffic flowing between internal users and http proxy. Snort listening on traffic flowing between internal proxy and external web servers. As anticipated, many rules are triggered on the
traffic between the internal proxy and the external web servers. BUT,
same rules are not triggered on same traffic between the http proxy and the internal users. What I am trying to achieve is see an alert between the internal http proxy and external webservers, and correlate to an alert on the same traffic, but as it flows between the internal users and the internal http proxy. For some reason, only the outside traffic is triggering the alert. To confirm snort and variables are setup correctly for testing so that I should see alerts, I confirmed can trigger rules on ICMP traffic between the internal http proxy and the internal users. It appears that the proxy is doing something to the traffic as it flows between the internal http proxy and the users, so that is not detected by snort rules. Any thoughts or suggestions on where to start tinkering? Thanks in advance, Scott Scott Gould Senior Network & Systems Analyst Gynecologic Oncology Group Statistical & Data Center scott.gould () gogstats org 716-845-5702 This email message may contain legally privileged and/or confidential information. If you are not the intended recipient(s), or the employee
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Current thread:
- Alert on contents of proxy traffic Gould, Scott (Nov 26)
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- Re: Alert on contents of proxy traffic Gould, Scott (Nov 26)
- Re: Alert on contents of proxy traffic Will Metcalf (Nov 26)
- Re: Alert on contents of proxy traffic Gould, Scott (Nov 26)
- Re: Alert on contents of proxy traffic Gould, Scott (Nov 26)
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