Re: Promiscious Device Detection

[Michael Holstein <michael.holstein () csuohio edu>]

> You can't search for promisc devices, as they don't advertise them-
> selves in any way. Chkrootkit[1], though, will check the local machine
> for a promisc interface, as well as other signs of possible badness.

Not entirely true .. you can use things like antisniff to spoof ARP 
packets and see what answers to ARP but not IP -- but that'll do you no 
good for a physically isolated tap -- like what happens when you use a 
passive fiber splitter and two cards utilizing the receive side only.

Also .. a really well firewalled machine will appear no different than 
one running a promisc. interface.

Generally though .. people up to no good on a switched network will have 
to do other things to get their promisc. interface to actually 
accomplish anything .. like ARP spoofing -- and *that's* detectable. As 
for 'global' taps, like Snort running on a whole network, best just 
assume it's there and react accordingly (eg: Fragrouter).

~Mike.
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