RE: how to bypass rouge machine detection techniques

["Cassidy Macfarlane" <cmacfarlane () Drummond-Miller co uk>]

> From the whitepaper:

"Empirical evidence has also shown that computers that are actively in
use
tend to broadcast rather frequently."

Read that as 'badly-configured computers'.  It is a no-brainer to not
broadcast from a machine that is 'rogue' - IE a prospective
attacker/wardriver would not 'announce' their presence on your network
by sending a whole load of broadcast packets.

Additionally, multiple virtual MACs could be created, and used to send
L2 b/casts to the sensor, thereby creating a mass of false positives,
and DOS-ing your IDS.

I just thought of these off the top of my head, I have no experience of
this particular software, but it does not seem too robust to me.  A
passive sniffer would not broadcast, but would sit on your network
happily sucking up packets.  To completely bypass the system, you could
simply spoof the IP/MAC of a trusted and registered system.


(BTW, it's spelt 'rogue'{there are about 14 instances of the bloody word
in the pdf you referenced} - 'rouge' is a kind of makeup.)

HTH


-----Original Message-----
From: full-disclosure-bounces () lists grok org uk
[mailto:full-disclosure-bounces () lists grok org uk] On Behalf Of Gaurav
Kumar
Sent: 11 July 2005 10:59
To: full-disclosure () lists grok org uk
Subject: [Full-disclosure] how to bypass rouge machine detection
techniques


Friends,

There are several techniques available for detecting rouge (not being
a member of trusted domain) machines, such as active scanning, active
directory querying etc, but I guess most powerful being the one used
by epolicy orchestrator. Its agents (deployed on each subnet) checks
for L2 broadcasts like Arp broadcast etc. After detecting a broadcast,
it used the mac address and ip address to proceed further to detect
whether the machine is rouge or not.

http://www.networkassociates.com/us/local_content/white_papers/wp_epo3_5
_rsdwhitepaper_july2004.pdf

I was wondering if this approach is foolproof and can be safely
deployed or if there is a way to bypass it?

Regards,
Gaurav
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