How to Block a Country in CSF firewall
To block all traffic from a country in CSF Firewall edit file /etc/csf/csf.conf
vi /etc/csf/csf.conf
Find the line
CC_DENY = ""
In this line, you can add 2 Letter country code. For example to block China and Russia, add
CC_DENY = "CN,RU"
Now you need to restart firewall with command
systemctl restart lfd csf -r