Install libpam-shield by entering the following commands in the terminal:
sudo apt update sudo apt install libpam-shield
Description:
locks out remote attackers trying password guessing
In certain situations it is not possible to use host based authentication and here pam-shield comes in use. . It locks out brute-force password crackers using null-route or iptables rules.
Homepage: http://github.com/jtniehof/pam_shield
Version: 0.9.6-1.3build1
Section: universe/admin