Fail2Ban: How To Install Fail2Ban to protect server from Brute Force SSH Login Attempts (Ubuntu):

Fail2Ban is a simple script designed to scan log files for repeated failed login attempts and to ban IP addresses that make too many failures. Commonly that’s a brute force attempt to find correct password combination to login to a server via SSH.

https://geekeasier.com/fail2ban-how-to-install-fail2ban-to-protect-server-from-brute-force-ssh-login-attempts-ubuntu/3774/