#!/bin/bash
mkdir /root/bin
touch /root/bin/ssh_brutforce.sh
chmod +x /root/bin/ssh_brutforce.sh
touch /root/bin/ssh.sh
chmod +x /root/bin/ssh.sh

cat <<EOCONFIG > /root/bin/ssh_brutforce.sh

#!/bin/sh
iptables -t filter -A INPUT -p tcp --destination-port 22 -m state --state NEW -m recent --set --name SSH -j ACCEPT
iptables -t filter -A INPUT -p tcp --destination-port 22 -m recent --update --seconds 60 --hitcount 4 --rttl --name SSH -j LOG --log-prefix "SSH_BRUTFORCE: "
iptables -t filter -A INPUT -p tcp --destination-port 22 -m recent --update --seconds 60 --hitcount 4 --rttl --name SSH -j DROP

EOCONFIG

cat <<EOCONFIG >> /etc/crontab

# ssh brutforce
* */3   * * * root /root/bin/ssh.sh > /dev/null 2>&1
EOCONFIG

cat <<EOCONFIG > /root/bin/ssh.sh

#!/bin/bash
ssh=`iptables -n -L | grep SSH_BRUTFORCE | awk '{print $27}'`

        if [ -z "$ssh" ];  then
        cd /root/bin && ./ssh_brutforce.sh
                fi

exit
EOCONFIG