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Network Security Security-Basics
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RE: what to do?

Subject: RE: what to do?
Date: Tue, 30 Aug 2005 07:15:44 -0300
        In this case make sure SSH is configured to use TCP Wrappers. If
it's not, it'll bypass hosts.allow and hosts.deny.
        Another possibility is to block the suspicious IP addresses on your
border firewall. If it's not under your responsibility, install some
filtering mechanism (e.g. iptables) on the SSH machine and filter out the
suspicious IP addresses.
        Regards,

        Eduardo Suzuki
        esuzuki_br@pop.com.br
        Eduardo.AC.Suzuki@gmail.com
 
-----Original Message-----
From: Jonathan Loh [mailto:kj6loh@yahoo.com] 
Sent: Saturday, August 27, 2005 1:05 AM
To: Bill Smith; security-basics@securityfocus.com
Subject: Re: what to do?

You could deny the host by entering 
ALL:80.68.204.50
in /etc/hosts.deny
or if this is your private machine.  Do what I do in /etc/hosts.allow enter
all
the IP's (ranges, hosts).  and in /etc/hosts.deny.  deny everybody.

IE.
/etc/hosts.allow
sshd:a.b.c.d e.f.g.h/snm [EXCEPT i.j.k.l[/snm]]
and in 
/etc/hosts.deny
ALL:ALL
This way you are only allowing various hosts access to your machine. 

This of course will not block ip spoofing but it will stop a lot of the
attacks.
If this is a corporate machine, I would do it the first way.  

--- Bill Smith <vinet138@yahoo.com> wrote:

Hi Guys,

I noticed that someone is trying to hacker into my
machine. Please see below is the content of
/var/log/security.
what I would like some advice of you guys is, what
will I do with these people?
btw, I do have FW

Cheers,

Bill

Aug 24 17:56:28 tiger sshd[8229]: Invalid user golfer
from 80.68.204.50
Aug 24 17:56:28 tiger sshd[8231]: Invalid user golfer
from 80.68.204.50
Aug 24 17:56:29 tiger sshd[8233]: Invalid user golfer
from 80.68.204.50
Aug 24 17:56:30 tiger sshd[8235]: Invalid user golf
from 80.68.204.50
Aug 24 17:56:31 tiger sshd[8237]: Invalid user golf
from 80.68.204.50
Aug 24 17:56:32 tiger sshd[8239]: Invalid user goose
from 80.68.204.50
Aug 24 17:56:32 tiger sshd[8241]: Invalid user goose
from 80.68.204.50
Aug 24 17:56:33 tiger sshd[8243]: Invalid user goose
from 80.68.204.50
Aug 24 17:56:34 tiger sshd[8245]: Invalid user gorges
from 80.68.204.50
Aug 24 17:56:35 tiger sshd[8247]: Invalid user gorges
from 80.68.204.50
Aug 24 17:56:35 tiger sshd[8249]: Invalid user gorges
from 80.68.204.50
Aug 24 17:56:36 tiger sshd[8251]: Invalid user gosling
from 80.68.204.50
Aug 24 17:56:37 tiger sshd[8253]: Invalid user gosling
from 80.68.204.50
Aug 24 17:56:38 tiger sshd[8255]: Invalid user gosling
from 80.68.204.50
Aug 24 17:56:38 tiger sshd[8257]: Invalid user gouge
from 80.68.204.50
Aug 24 17:56:39 tiger sshd[8259]: Invalid user gouge
from 80.68.204.50
Aug 24 17:56:40 tiger sshd[8261]: Invalid user gouge
from 80.68.204.50
Aug 24 17:56:40 tiger sshd[8263]: Invalid user graham
from 80.68.204.50
Aug 24 17:56:41 tiger sshd[8265]: Invalid user graham
from 80.68.204.50
Aug 24 17:56:42 tiger sshd[8267]: Invalid user graham
from 80.68.204.50
Aug 24 17:56:42 tiger sshd[8269]: Invalid user grahm
from 80.68.204.50
Aug 24 17:56:43 tiger sshd[8271]: Invalid user grahm
from 80.68.204.50
Aug 24 17:56:44 tiger sshd[8273]: Invalid user grahm
from 80.68.204.50
Aug 24 17:56:44 tiger sshd[8275]: Invalid user grandpa
from 80.68.204.50
Aug 24 17:56:45 tiger sshd[8277]: Invalid user grandpa
from 80.68.204.50
Aug 24 17:56:46 tiger sshd[8279]: Invalid user grandpa
from 80.68.204.50
Aug 24 17:56:47 tiger sshd[8281]: Invalid user green
from 80.68.204.50
Aug 24 17:56:48 tiger sshd[8283]: Invalid user green
from 80.68.204.50
Aug 24 17:56:48 tiger sshd[8285]: Invalid user green
from 80.68.204.50
Aug 24 17:56:49 tiger sshd[8287]: Invalid user grey
from 80.68.204.50
Aug 24 17:56:50 tiger sshd[8289]: Invalid user grey
from 80.68.204.50
Aug 24 17:56:50 tiger sshd[8291]: Invalid user grey
from 80.68.204.50
Aug 24 17:56:51 tiger sshd[8293]: Invalid user group
from 80.68.204.50
Aug 24 17:56:52 tiger sshd[8295]: Invalid user group
from 80.68.204.50
Aug 24 17:56:52 tiger sshd[8297]: Invalid user group
from 80.68.204.50
Aug 24 17:56:53 tiger sshd[8299]: Invalid user gryphon
from 80.68.204.50
Aug 24 17:56:54 tiger sshd[8301]: Invalid user gryphon
from 80.68.204.50
Aug 24 17:56:54 tiger sshd[8303]: Invalid user gryphon
from 80.68.204.50
Aug 24 17:56:55 tiger sshd[8305]: Invalid user gucci
from 80.68.204.50


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