Things to do generally

SSH

• Make sure you can't ssh in as root (connect as a user then sudo to root!)

• vim /etc/ssh/sshd_config

• Look for PermitRootLogin yes

• Change to PermitRootLogin no

• :wq to write and quit

Install fail2ban

• apt install fail2ban

• [optional, if you want mail - apt install sendmail]

• ufw allow ssh

• ufw enable

• cp /etc/fail2ban/fail2ban.conf /etc/fail2ban/fail2ban.local

• vim /etc/fail2ban/fail2ban.local

• cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

• vim /etc/fail2ban/jail.local

• Check it is working with

  • fail2ban-client status

Taken from the following pages

• Fail2ban