Snort mailing list archives
Re: Understanding within
From: James Lay <jlay () slave-tothe-box net>
Date: Wed, 15 Aug 2012 12:37:07 -0600
On 2012-08-15 12:34, Joel Esler wrote:
On Aug 15, 2012, at 2:01 PM, James Lay <jlay () slave-tothe-box net> wrote:On 2012-08-15 11:41, lists () packetmail net wrote:On 08/15/12 12:33, Joel Esler wrote:You cannot apply content keywords to pcre. (So, no, you can't do what you are asking)Right but he could use the /R flag (like distance:0) to make the PCRE relative to the last content match. You could also just PCRE-up your within. Example: content:"bleh"; content:"blah" within:14; pcre:"/bleh[^\r\n]{0,10}blah/"; PCRE version 7.8 2008-09-05 re> /bleh[^\r\n]{0,10}blah/ data> blehblah 0: blehblah data> bleh1234567890blah 0: bleh1234567890blah data> bleh12345678901blah No match data>Thanks gents...this does help. Not to beat a dead horse here...here's the original snippet from the email: The reference number for this fax is <a href="hxxp://pixeljunks.de/YRmJLNJv/index.html">min1_did12-1345023267-7176853217-25 For things like this should I just forget about the within statement, knowing that: content:"<a href=|22|http:"; fast_pattern; pcre:"/\x2f[a-z]{8}\x2f/i";James: SID: 22088 covers these redirection attempts. But maybe alert tcp $EXTERNAL_NET any -> $HOME_NET 25 (msg:"something bad this way comes"; flow:to_server,established; file_data; content:"<a href="|22|http|3a"; content:"index.html"; distance:0; within:30; pcre:"/\x2f[A-Z\d]{8}\x2f/i"; metadata:service smtp;) ? -- Joel Esler Senior Research Engineer, VRT OpenSource Community Manager Sourcefire
Ah sheesh...thanks again gents....leave it to me to recreate the wheel 8-| James ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ 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:
- Understanding within James Lay (Aug 15)
- Re: Understanding within lists () packetmail net (Aug 15)
- Re: Understanding within James Lay (Aug 15)
- Re: Understanding within Joel Esler (Aug 15)
- Re: Understanding within lists () packetmail net (Aug 15)
- Re: Understanding within James Lay (Aug 15)
- Re: Understanding within lists () packetmail net (Aug 15)
- Re: Understanding within Joel Esler (Aug 15)
- Re: Understanding within James Lay (Aug 15)
- Re: Understanding within James Lay (Aug 15)
- Re: Understanding within lists () packetmail net (Aug 15)