RE: ForeScout ActiveScout (was: Re: Intrusion Prevention)

["Adam Powers" <apowers () lancope com>]

I would also be curious to know how you deal with NATed addresses and
proxies when you're relying on OPSEC or other firewall policy
change-o-matic technologies?

Example: If I'm a bad guy accessing a server protected by ActiveScout
from behind Company A's corporate NATed address(es), how do you prevent
all the other users at Company A from being DOSed out of accessing the
resources on the protected server?


-----Original Message-----
From: Frank Knobbe [mailto:fknobbe () knobbeits com] 
Sent: Sunday, December 15, 2002 5:51 PM
To: focus-ids () securityfocus com
Subject: Re: ForeScout ActiveScout (was: Re: Intrusion Prevention)

Oded,

I have a few follow-up questions. Since you guys surely have the proper
intellectual property protection methods in place, I was hoping you
could explain in a bit more detail:


On Sun, 2002-12-15 at 12:15, Oded Comay wrote:

> - It is independent of the payload of the attack. This enables
detection
>   of attacks not known to the security community.

Please define 'independent of the payload', perhaps in a example. Right
now it sounds as if that sentence was taking of a marketing slick.

> - It is not sensitive to whether the attack comes from the same source
(IP
>   address) as the reconnaissance. Au contraire: this is actually where
it
>   shines.

And here is where I'm really curious about. How do you relate a packet
from IP address A to a scan that came from IP address B a week ago?
Consider using a simple class C with web, dns, and mail servers as an
example.

> - The detection is extremely accurate, allowing for automatic blocking
to
>   be enabled without fear of blocking legitimate business.

I would assume you are making use of a white-list. Would I still be able
to block half of the Internet through spoofs? Or are you watching the
completion of the initial 3-way h/s to avoid spoofs?

> - Attacks are detected at an extremely early stage, when the payload
>   usually has no impact (yet), allowing time for effective blocking
(using
>   a firewall, or tearing down TCP connection before the TCP window
opens
>   up).

Uhm... how can you determine if the data constitutes an attack when
there is no payload yet?


I'm mostly curious about the IP address claim. What kind of marker do
you use to identify an 'attacker' (read, human) so that you can say with
accuracy that it is the same guy now on this IP who was here days ago on
an other?

I'm really more concerned about the solution to the technical challenge.
I hope you can explain it publicly without a Non-Disclosure. After all,
your technology should be protected through patents and what-not. There
have been other vendors in the past who openly explained the technology
behind their products, and those vendors are still in business. Please
don't be afraid, but satisfy out longing for the technical truth, now
that you sparked our interest... 

Regards,
Frank