WHM / cPanel – cpHulk Banlist | WHM / cPanel – cpHulk Blacklist

If you have a web hosting account, VPS (Virtual Private Server), or dedicated server, you may find this article useful. For those of you that have WHM / cPanel with an addon called cpHulk Brute Force Protection, you probably get numerous e-mails throughout the day regarding people trying to Brute Force your server.

What is cpHulk Brute Force Protection?

cpHulk is a brute force protection system developed by the cPanel team and is exclusive to cPanel / WHM control panels. It has been integrated with cPanel version 11. With cpHulk, you can set a threshold for authentication attempts on services like POP3, cPanel, WHM, FTP, etc. After a certain number of failed login attempts, the brute force attacker will no longer be able to authenticate with your server.

Learn More About Brute Force Attacks and How to Prevent Them

Brute Force

A problem solving technique where a series of possible answers are worked out and each possibility is tested for accuracy. This technique is particularly useful on multiple choice problems.


The practice and study of hiding information. Modern cryptography intersects the disciplines of mathematics, computer science, and electrical engineering. Applications of cryptography include ATM cards, computer passwords, and electronic commerce.

Brute Force Attack

In cryptography, a Brute Force attack or exhaustive key search is a strategy that can in theory be used against any encrypted data by an attacker who is unable to take advantage of any weakness in an encryption system that would otherwise make his/her task easier. It involves systematically checking all possible keys until the correct key is found. In the worst case, this would involve traversing the entire search space.

The key length used in the encryption determines the practical feasibility of performing a Brute Force attack, with longer keys exponentially more difficult to crack than shorter ones. Brute Force attacks can be made less effective by obfuscating the data to be encoded, something that makes it more difficult for an attacker to recognize when he/she has cracked the code. One of the measures of the strength of an encryption system is how long it would theoretically take an attacker to mount a successful Brute Force attack against it.

Brute Force attacks are an application of Brute Force search, the general problem-solving technique of enumerating all candidates and checking each one.

Theoretical Limits

The resources required for a Brute Force attack scale exponentially with increasing key size, not linearly. As a result, doubling the key size for an algorithm does not simply double the required number of operations, but rather squares them. If a device existed that could Brute Force a 56-bit encryption key in one second, it would take that device 149.7 trillion years to Brute Force a 128-bit encryption key.


In case of an offline attack where the attacker has access to the encrypted material, he can try key combinations at his leisure without the risk of discovery or interference. However, database and directory administrators can take countermeasures against online attacks, for example by limiting the number of attempts that a password can be tried, by introducing time delays between successive attempts and locking accounts out after unsuccessful logon attempts. Website administrators may prevent a particular IP address from trying more than a predetermined number of password attempts against any account on the site.

The above information was taken from Wikipedia.

Share the cpHulk banlist to help prevent future Brute Force attacks on your server. Click the “Show code only” button to copy the cpHulk blacklist IPs. If you would like to contribute to the cpHulk banlist, please send an e-mail to info@michaelbrentecklund.com or use the contact form with the subject line: cpHulk Banlist or cpHulk Blacklist.


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