[55868] in North American Network Operators' Group
[dmoore@caida.org: Re: Symantec detected Slammer worm "hours" before]
daemon@ATHENA.MIT.EDU (k claffy)
Thu Feb 13 15:31:47 2003
Date: Thu, 13 Feb 2003 12:30:36 -0800
From: k claffy <kc@caida.org>
To: nanog@nanog.org
Cc: dm <dmoore@caida.org>
Errors-To: owner-nanog-outgoing@merit.edu
[david not on nanog list so am forwarding for him]
----- Forwarded message from David Moore <dmoore@caida.org> -----
Date: Thu, 13 Feb 2003 10:42:18 -0800
From: David Moore <dmoore@caida.org>
Subject: Re: Symantec detected Slammer worm "hours" before
To: k claffy <kc@caida.org>
Cc: Sean Donelan <sean@donelan.com>, nanog@merit.edu,
David Moore <dmoore@caida.org>
> On Thu, Feb 13, 2003 at 11:59:48AM -0500, Sean Donelan wrote:
> Wow, Symantec is making an amazing claim. They were able to detect
> the slammer worm "hours" before. Did anyone receive early alerts from
> Symantec about the SQL slammer worm hours earlier? Academics have
> estimated the worm spread world-wide, and reached its maximum scanning
> rate in less than 10 minutes.
So actually thinking about this a bit more, our numbers count from
when single well connected or a set of less well connected hosts
are infected. If a single (or small number) of infected machines
were on slow links (dsl/cable modem/etc) it might take them up to
about an hour to find the next vulnerable host (also depending on
luck and which cycle of the RNG they are in). So there might be
a longer startup period than we suggested if the worm was launched
in a poor environment.
However, at those rates, the scanning by the worm (small number of
hosts with tiny total bandwidth) would be well below the noise of
even "normal" port scanning activity. I find it difficult to
believe that that _at the time_ it would have been flagged as
suspicious. Perhaps going back through their logs after the growth
was over would have yielded something.
If it was running at a rate which on average took it an hour to
find the next vulnerable host, then if they had effective monitoring
of a /8, then they would have only seen 100-300 packets in that hour
(fewer the more vulnerable hosts that were out there; slower scanning
to not find one in an hour).
It's a little hard for me to believe that symantec would have noticed
this level of traffic, figured out that it was bad (although perhaps
some simple x86 code detector might have helped) and have told people
about it at this rate. In any case, if they did, then it's because
the worm was launched from a poor bandwidth environment, presumably
something that symantec can't control in the future.
-- david
----- End forwarded message -----
