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Date: Wed, 06 Apr 2005 11:56:29 -0400
To: Martin McCormick <martin@dc.cis.okstate.edu>,
	freebsd-security@freebsd.org
From: Mike Tancsa <mike@sentex.net>
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Subject: Re: What is this Very Stupid DOS Attack Script?
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At 11:49 AM 06/04/2005, Martin McCormick wrote:
>         We have been noticing flurries of sshd reject messages in
>which some system out there in the hinterlands hits us with a flood of
>ssh login attempts.  An example:
>
>Apr  6 05:41:51 dc sshd[88763]: Did not receive identification
>         string from 67.19.58.170
>Apr  6 05:49:42 dc sshd[12389]: input_userauth_request: illegal
>         user anonymous
>         Other than spewing lots of entries in to syslog, what is the
>purpose of the attack?  Are they just hoping to luck in to an open
>account?  The odds of guessing the right account name and then guessing
>the correct password are astronomical to say the least.


Actually, sadly the odds are far too good given the cost to run such a 
script.  Unless you force users to use GOOD passwords, they will use dumb 
ones.... Think Paris Hilton recently.  The cost to let a script like that 
go in the background and pound away at hosts that have open ssh access is 
zilch. If you have ftpd running anywhere, you will see similar attempts

         ---Mike