A dictionary attack, also known as a brute force attack, is a common method of gaining access to a system. The attacker will use a script to try every possible password combination to gain access to the account.
It usually takes tens of thousands of login attempts for a brute force attack to find the correct combination and be able to login regularly.
Prevent brute-force attacks with Fail2Ban
If you use strong passwords, this isn't a cause for concern. To protect your system from brute-force attacks, you can either run your SSH daemon on a different port or use a tool like Fail2ban.
How to block administrators from being notified by brute force?
DirectAdmin features a brute force monitor tool that sends out email notifications to all admins when brute force assaults are detected.
If you want to stop messages from being sent out but keep the IPs blacklisted, set hide brute force notifications=1 in your directadmin.conf file.
All you have to do is edit DirectAdmin.conf under /usr/local/directadmin/conf and add the following string: