Re: targetted SSH bruteforce attacks

[Emmanuel VERCHERE <emmanuel.verchere () gmail com>]

Hi Gary,

SSH daemons using password auth exposed to the Internet _do_ get
bruteforce attempts. I would not recommend moving it to a different port
than 22 as that would be of very, _very_ little help - rather switch to
public key auth (plus SPA if you're paranoid), et voila.
I don't think there's someone out there craving for _your_ box - but
scripts running from compromised hosts, scanning for password-protected
SSH daemons (as well as a bunch of known exploitable webapps and
services), trying to reach out for 'fresh meat', and as such expand the
zombie net? Definitely ;)

Cheers.
 


On Thu, 17 Jun 2010 07:48:18 -0400
Gary Baribault <gary () baribault net> wrote:

> Hello list,
>
>     I have a strange situation and would like information from the
> list members. I have three Linux boxes exposed to the Internet. Two of
> them are on cable modems, and both have two services that are publicly
> available. In both cases, I have SSH and named running and available
> to the public. Before you folks say it, yes I run SSH on TCP/22 and no
> I don't want to move it to another port, and no I don't want to
> restrict it to certain source IPs.
>
>     Both of these systems are within one /21 and get attacked
> regularly. I run Denyhosts on them, and update the central server once
> an hour with attacking IPs, and obviously also download the public
> hosts.deny list.
>
>     These machines get hit regularly, so often that I don't really
> care, it's fun to make the script kiddies waste their time! But in
> this instance, only my home box is being attacked... someone is
> burning a lot of cycles and hosts to do a distributed dictionary
> attack on my one box! The named daemon is non recursive, properly
> configured, up to date and not being attacked.
>
>     Is anyone else seeing this type of attack? Or is someone really
> targeting MY box?
>
> Thanks
>
>
> Gary Baribault
> Courriel: gary () baribault net
> GPG Key: 0x685430d1
> Signature: 9E4D 1B7C CB9F 9239 11D9 71C3 6C35 C6B7 6854 30D1
>
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                     Emmanuel VERCHERE
            everchere <at> everchere <dot> com
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