Hi David:
Its nice to know that you (and others too) are interested in
exploring/discussing such AI based approaches. it true that we need some
correlations among various data sources to gain more confidence and
information to label an event as attack. recently i worked on a very simple
approach to detect DoS (particulary SYN flood), wherein I correlated packet
rate and CPU time of the server. surprising I got 0% false positive. of
course it does not mean that in real environment, it WILL behave like this.
but experimentally its a good start. similarly, we can investigate the
usability of Fusion theory or association rules to find correlations among
events. My only concern, at this point, is the complexity of implementing
such methods. I am interested in implementing one, but again time is one
major constraint here.
Another point which I want to bring in here is "what should we look for in
HUGE data?" Any machine learning algo is as good as the data presented to
it. data should be as minimum as possible but MUST contain the attack
manifestation. so this is another problem of characterizing the attack.
ok I think its enough for now :-)
Sanjay
At 01:41 AM 7/27/2005, Swift, David wrote:
I believe added correlation and the programming of artificial
intelligence into security devices to be a key area of expansion for any
good security device over the next few years.
Companies like Counterpane are beginning to correlate offline data to
look for real attacks.
It is immensely more valuable to me for a device to let me know that
someone used a SYN-SCAN to find the open ports on my firewall followed
by a Fragmented packet with a TTL 1 higher than my firewall to map true
destinations by ICMP replies, who then sent a fragmented packet through
to an IP address on a port he previously found he could establish a
session on.
Any single packet or detected IDS event means little by itself, but the
combination and sequence of events from the same source should allow me
to increase the threat level of a given source, and correspondingly
adjust my responses up to the point where I dynamically harden my
firewall from his source address regardless of what data he's
transmitting, AND hopefully beginning the automation of forensic
analysis by doing things like a reverse DNS lookup, whois, and
dynamically sending identification packets to his IP to identify any
other characteristics (i.e. will he respond to a Netbios Name Lookup?
Can I discover his MAC address? RARP tables/responses).
I would enjoy the topic, but believe this should be a new discussion
thread however.
-----Original Message-----
From: Sanjay Rawat [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 26, 2005 1:52 AM
To: Richard Bejtlich; Swift, David
Cc: Mike Barkett; Nick Black; [email protected]
Subject: Re: Firewalls (was Re: IDS evaluations procedures)
Hi Richard
I am agreed on the difficulty in defining an attack properly. in fact
recently i joined a company as a kind as intrusion analyst. Before that
i
was in academic environment doing my PhD in IDS. what i observed is that
signatures are concentrating more on a particular exploit code rather
than
the true exploit/vulnerability. i am specifically talking about Snort
signatures. I feel that time has come when we should also look at some
AI/data mining/ machine learning techniques to get some more insight
into
the attacks, as now we have high computing devices. During my research,
i
experimented with many such techniques, but I dont find the
acceptability
of such techniques in commercial products. I know i may sound more
theoretical to all experienced network/system administrators, but i want
to
bring this issue into the focus. in this way, we can, at least, discuss
the
feasibility of such techniques and the problems associated with that.
i am looking forward to have some response from all.
thanks
Sanjay
>Hi David,
>
>All good points. If you can get past firewalls using various
>techniques, I'm sure others can bypass even your product, right?
>
>This is not an attack against you or any other prevention vendor. The
>unfortunate reality is that at some point a smart, unpredictable
>intruder will figure out how to bypass your prevention mechanism.
>Where does that leave an integrated/converged security device? Will
>it have any record at all that it was beaten? Probably not -- if it
>knew what was happening, it would have blocked the attack, correct?
>
>The problem I see with most security vendors is their assumption that
>they can even identify attacks properly. This is a problem because
>detection or prevention requires accurate attack identification. I
>gave up on perfect attack detection years ago, but I did not give up
>on intrusion detection or prevention as necessary parts of the
>security process. I am glad you and other vendors still work on this
>very tough problem!
>
>For my part, I try to identify when my preventative system has failed
>via policy enforcement failure detection. If that doesn't work, I'm
>also performing network transaction logging. Once I know (by
>non-technical means, perhaps) that I'm compromised, I have
>network-based evidence to guide my incident response and remediation
>process.
>
>I don't see do-it-all-in-one security appliances approaching the
>problem this way.
>
>I guess my view is biased because I do incident response for a living,
>and I constantly deal with failed security mechanisms. (Unfortunately
>for my clients,) I am as busy now (with all the great new gear we
>have) as I was seven years ago when I started.
>
>Sincerely,
>
>Richard
>http://www.taosecurity.com
>
>-----------------------------------------------------------------------
-
>Test Your IDS
>
>Is your IDS deployed correctly?
>Find out quickly and easily by testing it
>with real-world attacks from CORE IMPACT.
>Go to
http://www.securityfocus.com/sponsor/CoreSecurity_focus-ids_040708
>to learn more.
>-----------------------------------------------------------------------
-
Sanjay Rawat
Senior Software Engineer
INTOTO Software (India) Private Limited
Uma Plaza, Above HSBC Bank, Nagarjuna Hills
PunjaGutta,Hyderabad 500082 | India
Office: + 91 40 23358927/28 Extn 423
Website : www.intoto.com
Homepage: http://sanjay-rawat.tripod.com
------------------------------------------------------------------------
Test Your IDS
Is your IDS deployed correctly?
Find out quickly and easily by testing it
with real-world attacks from CORE IMPACT.
Go to http://www.securityfocus.com/sponsor/CoreSecurity_focus-ids_040708
to learn more.
------------------------------------------------------------------------
------------------------------------------------------------------------
Test Your IDS
Is your IDS deployed correctly?
Find out quickly and easily by testing it
with real-world attacks from CORE IMPACT.
Go to http://www.securityfocus.com/sponsor/CoreSecurity_focus-ids_040708
to learn more.
------------------------------------------------------------------------
Sanjay Rawat
Senior Software Engineer
INTOTO Software (India) Private Limited
Uma Plaza, Above HSBC Bank, Nagarjuna Hills
PunjaGutta,Hyderabad 500082 | India
Office: + 91 40 23358927/28 Extn 423
Website : www.intoto.com
Homepage: http://sanjay-rawat.tripod.com
------------------------------------------------------------------------
Test Your IDS
Is your IDS deployed correctly?
Find out quickly and easily by testing it
with real-world attacks from CORE IMPACT.
Go to http://www.securityfocus.com/sponsor/CoreSecurity_focus-ids_040708
to learn more.
------------------------------------------------------------------------
