[CentOS] Paranoid Firewalling
ethericalzen at gmail.com
Thu Sep 8 13:41:57 UTC 2005
Kirk Bocek wrote:
> No! It's my secret! Bu-Wa-Ha-Ha! (or however that's spelled...)
> Okay, you forced it out of me...
> Sam Drinkard wrote:
>> If you don't mind, could you let me know where that script is? I'm
>> seeing the same thing -- kiddies trying to log in. I use something
>> similar, but manual entry on my mail server that is in a co-lo site
>> running FreeBSD. Here at home, I thought I'd be pretty well protected
>> behind the router, but I have to have the ssh port open, and I'm
>> seeing hundreds of attempts.
>> Kirk Bocek wrote:
>>> Good question Alex. However, I've never studied the scripts that
>>> 'script kiddies' use and so have no answer.
>>> Part of what has prompted this change is the recent surge of
>>> brute-force password attacks. From the timing of the password
>>> attempts, it's clear that these are script driven.
>>> I found a perl script that watches for failed logins. After a
>>> configurable number, the script enters the IP address into
>>> /etc/hosts.deny. After a configurable number of days, the script then
>>> removes the IP address.
>>> What I see in /var/log/secure is a whole series of 'Invalid user'
>>> messages followed by 'Failed password for invalid user' messages.
>>> These will then, because of the script, be terminated by a 'refused
>>> connect from' message when the address is entered into hosts.deny.
>>> My point in all this is that I only ever see *one* 'refused connect'
>>> message. So at least for this script, it gives up when it can't
>>> connect anymore.
>>> Kirk Bocek
Thanks for that linkage. And your previous explanation of what you
were seeing. Sorry I've been ill so couldnt' check the list until
today. Really appreciate it.
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