[prev in list] [next in list] [prev in thread] [next in thread] 

List:       snort-sigs
Subject:    Re: [Snort-sigs] Understanding within
From:       James Lay <jlay () slave-tothe-box ! net>
Date:       2012-08-15 18:37:07
Message-ID: fefcf0dd913a0b82d0c1b72d31dc6d3d () localhost
[Download RAW message or body]

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!
[prev in list] [next in list] [prev in thread] [next in thread]