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Forked from klepsydra/sync-fail2ban.sh
Created January 11, 2024 15:11
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Block globally reported hack attempts using your local iptables firewall rules
#!/bin/bash
## Update fail2ban iptables with globally known attackers.
## Actually, runs 100% independently now, without needing fail2ban installed.
##
## /etc/cron.daily/sync-fail2ban
##
## Author: Marcos Kobylecki <fail2ban.globalBlackList@askmarcos.com>
## http://www.reddit.com/r/linux/comments/2nvzur/shared_blacklists_from_fail2ban/
## Quit if fail2ban is missing. Maybe this fake requirement can be skipped? YES.
#PROGRAM=/etc/init.d/fail2ban
#[ -x $PROGRAM ] || exit 0
datadir=/etc/fail2ban
[[ -d "$datadir" ]] || datadir=/tmp
## Get default settings of fail2ban (optional?)
[ -r /etc/default/fail2ban ] && . /etc/default/fail2ban
umask 000
blacklistf=$datadir/blacklist.blocklist.de.txt
mv -vf $blacklistf $blacklistf.last
badlisturls="http://antivirus.neu.edu.cn/ssh/lists/base_30days.txt http://lists.blocklist.de/lists/ssh.txt http://lists.blocklist.de/lists/bruteforcelogin.txt"
iptables -vN fail2ban-ssh # Create the chain if it doesn't exist. Harmless if it does.
# Grab list(s) at https://www.blocklist.de/en/export.html . Block.
echo "Adding new blocks:"
time curl -s http://lists.blocklist.de/lists/ssh.txt http://lists.blocklist.de/lists/bruteforcelogin.txt \
|sort -u \
|tee $blacklistf \
|grep -v '^#\|:' \
|while read IP; do iptables -I fail2ban-ssh 1 -s $IP -j DROP; done
# Which listings had been removed since last time? Unblock.
echo "Removing old blocks:"
if [[ -r $blacklistf.diff ]]; then
# comm is brittle, cannot use sort -rn
time comm -23 $blacklistf.last $blacklistf \
|tee $blacklistf.delisted \
|grep -v '^#\|:' \
|while read IP; do iptables -w -D fail2ban-ssh -s $IP -j DROP || iptables -wv -D fail2ban-ssh -s $IP -j LOGDROP; done
fi
# prepare for next time.
diff -wbay $blacklistf.last $blacklistf > $blacklistf.diff
# Saves a copy of current iptables rules, should you like to check them later.
(set -x; iptables -wnv -L --line-numbers; iptables -wnv -t nat -L --line-numbers) &> /tmp/iptables.fail2ban.log &
exit
# iptables v1.4.21: host/network `2a00:1210:fffe:145::1' not found
# So weed out IPv6, try |grep -v ':'
## http://ix.io/fpC
# Option: actionban
# Notes.: command executed when banning an IP. Take care that the
# command is executed with Fail2Ban user rights.
# Tags: See jail.conf(5) man page
# Values: CMD
#
actionban = iptables -I fail2ban-<name> 1 -s <ip> -j <blocktype># Option: actionunban
# Notes.: command executed when unbanning an IP. Take care that the
# command is executed with Fail2Ban user rights.
# Tags: See jail.conf(5) man page
# Values: CMD
#
actionunban = iptables -D fail2ban-<name> -s <ip> -j <blocktype>
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