Penetration Testing mailing list archives
RE: OT: the detection of illegal gateways
From: "Demetris Papapetrou" <dpapapetrou () internalaudit gov cy>
Date: Tue, 25 May 2010 09:23:13 +0300
Hi all, You can Ping the workstations in each subnet using a spoofed source IP address. You need to do this from within your network (from different locations depending on your filtering rules). The spoofed IP will be the one utilized by a second machine you control on the Internet. The workstations will receive the spoofed packets and they will reply by sending their packets to the Internet through their default gateway. If their default gateway is an unauthorized routing device then its public IP address will be captured by your Internet connected machine. You can assign a unique number to each packet to make it easier for you to identify from which machine the reply originated. Prerequisite: The offending workstations must be switched on, they must be reachable from your location and they must reply to the packets you send them. Demetris Papapetrou Internal Audit Officer Republic of Cyprus Internal Audit Service Tel.: 22450386 email: dpapapetrou () internalaudit gov cy -----Original Message----- From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On Behalf Of Lee Sent: Saturday, May 22, 2010 5:43 PM To: J Hein Cc: pen-test () securityfocus com Subject: Re: OT: the detection of illegal gateways There's been a lot of good suggestions for finding 'illegal' routers. The two I like the best are:
5) talk with purchasing dept and give them 'keywords' that they can use to look through purchases to see where an internet connection may have been purchased with a corporate credit card ... 7) if all internet traffic is supposed to pass through an internet
firewall
or proxy, look for "lack of traffic" from IP blocks on your WAN. Even a regular windows machine sitting at rest is sending out queries to windows update, NTP, DNS, etc.
What I haven't seen mentioned yet is using Netflow to report on layer 2 traffic. If you're ok with writing your own software & the customer has the right hardware you could try modifying he cisco TCL Portscanner (http://www.packetlevel.ch/html/cisco/ciscotcl.html) to loop thru all addresses on the user subnet doing a ip route $internetWebServer 255.255.255.255 $host connect $internetWebServer 80 no ip route $internetWebServer 255.255.255.255 $host to find the 'illegal' routers. Regards, Lee On 5/17/10, J Hein <j.hein () ymail com> wrote:
hi all, this post might be somewhat off-topic, so please accept my apologies
first.
I have a somewhat difficult problem to crack - there is a large corporate network which covers several Nordic countries, and unfortunately there
have
been cases in the past where a device with routing capability has been plugged into the network (for creating a "faster" connection to the
internet
for a branch office). Because this violates corporate policies and creates "invisible" entry points to the internal network, I have been given a task to find a suitable software for finding such kind of illegal routers. Are there any good products for detecting illegally installed boxes with a routing capability? One of my fellow consultants suggested IP Sonar (by Lumeta) for this purpose which (as he claims) has been successfully used
by
BT in the past. From the product description I've got an impression that
IP
Sonar cleverly uses traceroute for detecting routers that illegally
exchange
information between internal networks and the internet (so called "network leaks"). I understand that router detection is a complex issue, and in order to address this problem fully, one needs to analyze traffic that flows
through
all key routers and switches in the whole corporate network.
Unfortunately,
since the deployment of such monitoring system takes a lot of time, I'd
like
to begin with a relatively simple solution which attempts to locate
network
leaks by polling the network from few points only (like IP Sonar does,
using
traceroute for that purpose). Can anyone recommend any such commercial or open source tools? (open
source
utilities would actually be my preference :) Also, what is your
experience
with IP Sonar -- is it really a good stuff? Thanks in advance :) -- jhein ------------------------------------------------------------------------ This list is sponsored by: Information Assurance Certification Review
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------------------------------------------------------------------------ This list is sponsored by: Information Assurance Certification Review Board Prove to peers and potential employers without a doubt that you can actually do a proper penetration test. IACRB CPT and CEPT certs require a full practical examination in order to become certified. http://www.iacertification.org ------------------------------------------------------------------------ ------------------------------------------------------------------------ This list is sponsored by: Information Assurance Certification Review Board Prove to peers and potential employers without a doubt that you can actually do a proper penetration test. IACRB CPT and CEPT certs require a full practical examination in order to become certified. http://www.iacertification.org ------------------------------------------------------------------------
Current thread:
- OT: the detection of illegal gateways J Hein (May 18)
- Message not available
- Re: OT: the detection of illegal gateways Zack Payton (May 19)
- Re: OT: the detection of illegal gateways Adam Mooz (May 19)
- RE: OT: the detection of illegal gateways John Lampe (May 21)
- Re: OT: the detection of illegal gateways Zack Payton (May 19)
- Message not available
- Re: OT: the detection of illegal gateways ulric (May 19)
- Re: OT: the detection of illegal gateways BMF (May 21)
- Re: OT: the detection of illegal gateways Kurt Buff (May 21)
- Re: OT: the detection of illegal gateways Lee (May 24)
- RE: OT: the detection of illegal gateways Demetris Papapetrou (May 25)
- RE: OT: the detection of illegal gateways Ward, Jon (May 26)