Step 1: To access the IP Deny Manager, click on the corresponding icon in the Security section of your cPanel interface.
Step 2: Enter the IP address or domain name you wish to deny access to in the blank field next to IP Address or Domain: (You can enter an IP block such as 1.2.3. to deny access to all IPs that start with 1.2.3.).
Step 3: Click on Add.
You're done!