Security Incidents mailing list archives

Re: Weird SSH attack last night and this morning (still ongoing)


From: Gary Baribault <gary () baribault net>
Date: Wed, 07 May 2008 17:07:24 -0400

Yeah, but I'm a masochist, I run these servers for the fun of it and to see what's happening on the net. I see all of the background static and every now and again I see somehting fun like this!

Gary Baribault
Courriel: gary () baribault net
GPG Key: 0x4346F013
GPG Fingerprint: BCE8 2E6B EB39 9B23 6904 1DF4 C4E6 2CF7 4346 F013




Darren Bolding wrote:
And, not to pretend that it adds any great additional security to any sort of attack, but running sshd on a non-standard port reduces the number of scans/attacks I see dramatically- to the point that I actually rarely see any connection attempts from anyone other than authorized users. It's simple, fast and doesn't require any packages installed or anything.

But that may not be an option for all user communities.

--D

On Wed, May 7, 2008 at 10:53 AM, Erin Carroll <amoeba () amoebazone com <mailto:amoeba () amoebazone com>> wrote:

    Gary,

    I am seeing the exact same traffic pattern & attempts as of
    ~10:20pm PST:
    Single attempts to remote root ssh from disparate IP's with few
    (if any)
    repeated source location. So now we have a sample size of 2 :)

    When I saw this hitting my servers last night I thought it an odd
    attack
    pattern but surmised it was either a targeted slow attack with
    spoofed IP's
    or a "slow roll" botnet using throttled connects to try flying
    under the
    radar for alerting. I was leaning toward the latter and even more
    so now
    that I see my organization isn't the only one.

    Just block root ssh and apply a source IP whitelist for valid non-root
    allows if you require remote ssh for day to day. I consider it bad
    security
    practice to allow remote root ssh anyway. People should use user
    accounts
    and a sane sudoers config instead.



    --
    Erin Carroll
    Moderator, SecurityFocus pen-test mailing list
    amoeba () amoebazone com <mailto:amoeba () amoebazone com>
    "Do Not Taunt Happy-Fun Ball"



    -----Original Message-----
    From: Gary Baribault [mailto:gary () baribault net
    <mailto:gary () baribault net>]
    Sent: Wednesday, May 07, 2008 5:27 AM
    To: incidents () securityfocus com <mailto:incidents () securityfocus com>
    Subject: Weird SSH attack last night and this morning (still ongoing)

    I don't know what is going on last night and this morning ... I have
    three Linux servers facing the Internet, two on cable modems and
    another
    on a static IP/commercial connection and this last one is a
    gateway to a
    Web/FTP/SMTP/Pop3/NTP Linux based system.

    I have DenyHosts installed on all three and have blocked about 75
    attempts ..  from known compromised adresses .. The log shows
    (obviously) that there where even more attempts from adresses that are
    unknown to DenyHosts but there was only one login attemps per
    adress and
    it was with the Root account .. which is obviously blocked in my sshd
    config ..

    Of the three machines, one of them only had about 10 attempts, but the
    other two had about 200 attempts .. all of them with only 1 try
    with the
    user Root ..

    Is any one else seing this? or am I being targeted? This is still
    going
    on now .. and it started arround 10:00 last night GMT+4

    --
    Gary Baribault
    Courriel: gary () baribault net <mailto:gary () baribault net>
    GPG Key: 0x4346F013
    GPG Fingerprint: BCE8 2E6B EB39 9B23 6904 1DF4 C4E6 2CF7 4346 F013




--
-- Darren Bolding --
-- darren () bolding org <mailto:darren () bolding org> --


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