RE: Illegal user ssh probes
From: Robert Schultz (rhs_at_umich.edu)
Date: Wed, 29 Sep 2004 10:50:59 -0400 (EDT) To: firstname.lastname@example.org
i wrote this to frank directly but the wider group may find it of
interest. the attack origins are not limited to one geopolitical region:
hi frank -
i saw this came up last month on my logs and it was noted on the NetSec
list, which fwd'd the EDUCAUSE Security list msgs:
hope this helps -robert
On Tue, 28 Sep 2004, Huijsmans, JCM (Jan) wrote:
> > On examining /var/log/secure for several firewalls I manage
> > remotely using
> > ssh I have observed a recurrent pattern of probing over the
> > last several
> > that attempts to connect using user id's in the following order...
> > test / guest / admin / admin / user / test
> We are seeing the same on 1 of the systems of my private company, coming from several systems from the former eastern europe. (mostly 80.x.x.x) In our set of users they try are also the user root and an attempt without a user (NO_USER or something like that, I don't have access to the logs right now)
> > However I am wondering if anyone has characterised the probe and/or
> > performed a risk assessment/analysis? The rate of probes is
> > very low so I don't think there is a DOS attack just yet!
> Not yet, but on our system we're see a probe pop up every 2-3 hours. (started with 1 every 2-3 days)
> > Is it worth reporting the behaviour to the net block
> > assignees in case they
> > aren't aware their server might be compromised?
> I think we should at least compare the ip blocks off list to see if there are similarities.
> Jan Huijsmans
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