From: Rogan Dawes (discard@dawes.za.net)
Date: Thu Sep 02 2004 - 03:08:55 EDT
vinay mangal wrote:
> Dear all,
>
> Thanks for your suggestions. May be I am not able to define my question
> properly.
>
> This problem is strictly with in company internet access firewall and in the
> LAN only. In a company, policy for Internet access says it is through IP
> only. The others can not browse the internet. This policy is implemented on
> firewall. Few smart guys have installed free proxy server running on non
> default ports and distributed the internet access to their friends. The
> firewall sees the traffic coming from the authorized IP and does not stop
> them. We want to know who has installed proxy on there machine.
>
> I hope, I am able to clearly define my question. Thanks
>
>
> vinay
In that case, you should be looking for traffic destined for a proxy
server in your network.
e.g.
ngrep "HTTP/1" dst net yournetwork
or something similar.
Of course, if your network is switched, you will not see the traffic you
need unless your sniffer is attached to a mirrored port on your switch.
My recommendation is to have the security policy redistributed (if it
already contains such prohibitions) or updated, and then point out to
all your users that contravention of the security policy is a firing
offence.
Your best bet to identify violators is to use (a variation of) the ngrep
mentioned above, but make sure that you are seeing the necessary traffic
via the switched port.
Hope this helps.
Rogan
-- Rogan Dawes *ALL* messages to discard@dawes.za.net will be dropped, and added to my blacklist. Please respond to "lists AT dawes DOT za DOT net" ------------------------------------------------------------------------------ Ethical Hacking at the InfoSec Institute. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors. Check out our Advanced Hacking course, learn to write exploits and attack security infrastructure. Attend a course taught by an expert instructor with years of in-the-field pen testing experience in our state of the art hacking lab. Master the skills of an Ethical Hacker to better assess the security of your organization. http://www.infosecinstitute.com/courses/ethical_hacking_training.html -------------------------------------------------------------------------------
This archive was generated by hypermail 2.1.7 : Sat Apr 12 2008 - 10:54:03 EDT