apt-get update && apt-get upgrade && apt-get dist-upgrade
apt-get install ufw && ufw enable
Turn off root in sshd_config (Covered)
if grep -qF 'PermitRootLogin' /etc/ssh/sshd_config; then sed -i 's/^.*PermitRootLogin.*$/PermitRootLogin no/' /etc/ssh/sshd_config; else echo 'PermitRootLogin no' >> /etc/ssh/sshd_config; fi
PermitRootLogin no