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May 19, 2015 - A Look At The New Commandlinefu
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Block all IP addresses and domains that have attempted brute force SSH login to computer

Terminal - Block all IP addresses and domains that have attempted brute force SSH login to computer
(bzcat BZIP2_FILES && cat TEXT_FILES) | grep -E "Invalid user|PAM" | grep -o -E "from .+" | awk '{print $2}' | sort | uniq >> /etc/hosts.deny
2010-01-03 04:41:51
User: jayhawkbabe
Functions: awk cat grep sort uniq
Block all IP addresses and domains that have attempted brute force SSH login to computer

Searches all log files (including archived bzip2 files) for invalid user and PAM authentication errors, both of which are indicative of brute force attempts at logging into computer. A list of all unique IP addresses and domain names is appended to hosts.deny. The command (and grep error messages) will work on Mac OS X 10.6, small adjustments may be needed for other OSs.


There are 4 alternatives - vote for the best!

Terminal - Alternatives
/usr/sbin/iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent -set
2010-01-28 00:51:49

I use iptables. To rate limit connections. Very easy and no ban lists to manage.

Know a better way?

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What others think

What if I just incorrectly type my password a couple of times?

Comment by kaedenn 432 weeks and 4 days ago

Would it be possible to do it for every IP that had more than 5 failed login attempts?

Comment by gromburger 432 weeks and 4 days ago

install the denyhosts package or fail2ban to get this automated for you. Good++ use of the commandline though :)

Comment by linuxrawkstar 432 weeks and 3 days ago

like linuxrawkstar said...

"sudo apt-get install fail2ban"

Comment by DrAzraelTod 432 weeks and 1 day ago

@linuxrawkstar @DrAzraelTod Already installed denyhosts. :) The Mac-specific corrections are wrong on the website. Above command helped me figure out regexes for denyhosts. Love python and regexes.

Comment by jayhawkbabe 432 weeks ago

Your point of view

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