OS fingerprinting technique

Carefully studying the way TCP works, especially some timer value
inside the TCP stack, we have derived on a new technique for remote OS
detection, based on temporal response analysis.

The idea is quite simple: send a TCP SYN packet to an open port on a
remote system, and listen the different answers (usually successive
SYN/ACK packets). By measuring the number of response, the delay
between retries, and the optional presence of a "RST" packet after a
few answers, we can easily recognize some operating systems.
The nice thing is that it only required to send one packet on an open
TCP port, which make this method really quiet.

As a proof of concept, we also developed a standalone tool "RING"
that will perform these testings and identifications, using a signature
file.

More information is available at:
http://www.intranode.com/site/techno/techno_articles.htm

The open source tool can be downloaded from:
http://www.intranode.com/site/techno/ring-0.0.1.tar.gz

The full, 13 pages, white paper is available at:
http://www.intranode.com/pdf/techno/ring-full-paper.pdf

We will be very happy to get your feedback on this technique.
Feel free to contact us at: ring_at_intranode.com

Thanks,

-Franck

-- 
Franck Veysset    --   http://www.INTRANODE.com
       Intranode Software Technologies
It is always possible to aglutenate multiple separate 
problems into a single complex interdependent solution.
In most cases this is a bad idea. (RFC 1925)
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