Re: DDOS Attack Mitigation

[aleph1 () SECURITYFOCUS COM (Elias Levy)]

Some updates and suggestions made by others to my earlier comments.

Egress Filtering
----------------

Chris Brenton <cbrenton () sover net> reminded us of the flip coin of
ingress filtering, egress filtering. It can be used by networks
connecting to the Internet to make sure they are not a source of
spoofed packets.

You can find information about it at:
http://www.sans.org/y2k/egress.htm

Spoofed Packet Tracing
----------------------

Chris also pointed out a presentation by Robert Stone from UUNET given
at NANOG on CenterTrack. CenterTrack is an overlay network that allows
you easily determine the ingress network edge router of packets.
This makes it easy to track down the source of spoofed packets.
You can find the presentation slides at:
http://www.nanog.org/mtg-9910/robert.html

Network Auditing Tools
----------------------

David Brumley <dbrumley () rtfm stanford edu> pointed out the is at least
one other free scanning tool called RID that will detect the presence of
Trinoo, TFN, or Stacheldraht clients. You can find this tool at:
http://theorygroup.com/Software/RID/

Axent has released an updated test for NetRecon to find hosts with
DDOS agents.
http://www2.axent.com/swat/News/nr30su1.htm

ISS's Internet Scanner 6.01 will find hosts with DDOS agents.

Intrusion Detection
-------------------

Axent has released an updated signature for NetProwler to detect
DDOS attacks and communication with the DDOS agents.
http://www2.axent.com/swat/3download_np.htm

ISS's RealSecure 3.2.1 will detect DDOS attacks and communication to
with the DDOS agents.

The Obvious
-----------

Secure your machines. It won't stop you from being a victim of a DDOS
attack but it will stop someone using you as a launching point for the
attacks. You may be found liable if someone uses your network and hosts
to attack someone else.

Snake Oil
---------

You should also be aware the are a number of companies out there
that claim to have solutions to DDOS attacks that they will happily
sell you. You should be skeptical of anyone peddling a "silver bullet"
solution. Caveat emptor.

--
Elias Levy
SecurityFocus.com
http://www.securityfocus.com/