[Snort-sigs] Couple sigs

James Lay jlay at ...3266...
Mon Sep 10 10:22:27 EDT 2012


On 2012-09-10 07:52, Alex Kirk wrote:
> With, that is, some tweaks to be slightly less specific. If you can 
> be
> evaded by simply switching the order of the width and height on the
> first one, for example, well, youre probably less than useful.
>

Thanks Alex.  For the hidden iframe, I'm thinking maybe something like 
the below:

alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any 
(msg:"INDICATOR-COMPROMISE Hidden iframe"; flow:to_client, established; 
file_data; content:"<iframe"; content:"width="; content:"height="; 
pcre:"/=[0-1]/ms"; content:"style=visibility|3a|hidden"; 
classtype:bad-unknown; sid:10000023; rev:2;)

I was thinking a byte_test that will test to see if width= or height= 
are less than say 2, but I haven't yet figured out how to get that to 
fly, so I guess the pcre will suffice for now.  This alerts on my packet 
cap, and so far no FP's running live.  You think some within statements 
might help?  Thanks Alex.

James




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