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Re: [Full-disclosure] what can be done with botnet C&C's?


From: "Payam Tarverdyan Chychi" <payam () bhsecurity com>
Date: Sun, 13 Aug 2006 11:24:22 -0700 (PDT)


Though placing a /32 to a discarded interface helps the situation, you are
now fully disabling your client that uses the /32... I do agree that it
definitely helps the situation... specially when the attack is a few mil
pps or perhaps even few gigs/sec  in which case a customer /32  or bigger…
being down is about 100x better then your network being down.

so my question is then how do you use the same method for your peering
sessions (assuming you do peering on a private or public level)... seeing
how 95% of peers will not allow such specific entries such as /32 into
their tables... so in case of an attack you are left with either having to
take down the peering session or stop advertising the prefix though that
peer.

Just curious as to how you go about it...

cheers,
-Payam




I hate to stir the flames again, but this idea sounds a lot like RBLs.  :)

All kidding aside, I'm curious as to when we will reach the point where
the devices of our networks will be able to share information regarding
sporadic bursts or predefined traffic patterns in network traffic within
a certain time frame, determine it is a related outgoing (or incoming)
attack, and mitigate/stop the traffic. I think it certainly is possible
to accomplish this on a per-router level, but being able to have the
devices communicate and share information between one another is a
completely separate thing. (New protocol perhaps.)

The only real method that I really have in my toolkit to stop incoming
DDoS on a AS-wide perspective is originating a /32 within an AS with a
next-hop of a discard interface.

Something similar to that nature but more flexible and designed for the
sole purpose of preventing/stopping abuse would be a very nice feature.

Cheers.
-Michael

--
Michael Nicks
Network Engineer
KanREN
e: mtnicks () kanren net
o: +1-785-856-9800 x221
m: +1-913-378-6516

Payam Tarverdyan Chychi wrote:
 I’ve been reading on this subject for the last several weeks and it
seems
as if everyone just like to come up with out of the box ideas that are
not realistic for today’s network environments

J.Oquendo, thanks for the Smurf example … as there are still
admins/engineers at large networks that have no clue as to what they
are doing… so QoS is for sure out of the question.. at least at this
time.

Depending on agents to take actions and protecting our networks is even
a
bigger joke. Back in late 90s where kiddies were using the simplest
types
of C&C, open wide irc networks with visible Channels and no encryptions…
and agents couldn’t do anything unless the attack was big enough to take
down Amazon, yahoo, Microsoft or some other major provider with enough
$$$
to start an investigation.

So what makes you think that agents are of any help in today’s world
where
c&c have gotten so much more sophisticated, use backup private servers,
encryption, tunneling and much much more..

In my opinion, the only way to really start cracking down on c&c and put
an end to it is the cooperation of major ISP’s. I realize that most
isp’s
cant/wont setup a security team to just investigate c&c / attacks (would
this really fall under the Abuse team?) but perhaps If all major
networks
worked together and created a active db list of c&c found either on
their
networks or attacking ones network… then it would be much much easier to
trace back c&c and dispose of them.

Unfortunately, we don’t live in a perfect world and most isp’s hate
sharing any information… I guess its better for them to have a bigger
ego
than a safer / more stable network…

Please feel free to correct me if I am wrong…

-Payam



-- 
-- 
Payam Tarverdyan Chychi
Network Analyst



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