What Are Brute Force Attacks? How To Prevent & Stop Them?

In the world of Cyber crimes, brute force attack is an activity that involves repetitive successive attempts of tryingvaried password combinations to break into any web site. This attempt is carried out vigorously by the hackers who also make use of bots they need installed maliciously in different computers to boost the computing power required to run such form of attacks.

What Is A Brute Force Attack ?

A brute force attack is a trial-and-error based method used to acquire information such as a username and password. Attackers frequently use automated code to generate a large number of consecutive guesses.To improve efficiency, an attacker might use a dictionary attack using common or default passwords.

The attacker aims to forcefully gain access to a user account by trying to guess the username/email and password. Usually, the motive behind it is to use the breached account to execute a large-scale attack, steal sensitive data, shut down the system, or a combination of the three.

Creating code that executes this type of attack does not take much imagination or information, and there are even widely out there automated tools that submit several thousand password attempts per second.

Hackers Motive Behind The Act.

Behind brute force attack, hackers motive is to achieve illegal access to a targeted web site and utilize it in either executing another kind of attack or stealing valuable data or just shut it down. it is also possible that the attacker infect the targeted web site with malicious scripts for future objectives without even touching one thing and leaving no trace behind. Therefore, it is recommended to run frequent scans and follow best practices to secure your web site.

Brute Force Attack Prevention Techniques

There are several methods to stop or prevent brute force attacks. the most obvious is a strong password policy. Each web application or public server should enforce the use of strong passwords (i.e., for standard user accounts at least eight letters; numbers, uppercase and lowercase letters, and special characters required) and require frequent password changes.

Lets investigate additional, less obvious, ways to stop a brute force attack.

• Password Length
• Password Complexity
• Limit Failed Login Attempts
• Modifying .htaccess file
• Make the Root User Inaccessible via SSH
• Modify the Default Port
• Use CAPTCHA
• Limit Logins to a Specified IP Address or Range
• Two Factor Authentication
• Unique Login URLs
• Monitor Server Logs

Password Length :-

The first step towards Brute Force Attack prevention should be longer password length. Nowadays many websites and platforms enforce their users to create a password of certain length (8 – 16 characters).

Password Complexity :-

Another important thing is to create a complex password. It is not recommended to create passwords like "ilovemycountry" or "password123456"; instead your password should consist of UPPERCASE and lowercase alphabets and should also have numbers and special characters. Complexity of the password delays the cracking process.

Limit Failed Login Attempts :-

As stated above, implementing an account-lockout after several unsuccessful login attempts is ineffective as it makes your server easy prey for denial-of-service attacks. However, if performed with progressive delays, this method becomes much more effective.

Account lockouts with progressive delays lock an account only for a set amount of time after a designated number of unsuccessful login attempts. This means that automated brute force attack tools will not be as useful, while your admin will not have to deal with unlocking several hundred accounts every 10 minutes or so.

Modifying .htaccess file :-

Adding a few rules in .htaccess file can further harden the security of your WordPress site. Objective is to allow access to wp-admin to only specific IP addresses listed in .htaccess file.

Make the Root User Inaccessible via SSH :-

SSH brute force attempts are often carried out on the root user of a server. Make sure to make the root user inaccessible via SSH by editing the sshd_config file. Set the "DenyUsers root" and "PermitRootLogin no" options.

Modify the Default Port :-

Most automated SSH attacks are attempted on the default port 22, so running sshd on a different port could prove to be a useful way of dealing with brute force attacks.

To switch to a non-standard port, edit the Port line in your sshd_configfile.

Use CAPTCHA :-

We are all pretty much used to seeing CAPTCHA all over the internet. Nobody likes trying to make sense of something that looks like it’s been scribbled by a two-year-old, but tools such as CAPTCHA render automated bots ineffective. That single requirement to enter a word or the number of cats on a generated image is highly effective against bots, even though hackers have started using optical character recognition tools to get past this safety mechanism.

Bear in mind that the use of tools such as CAPTCHA negatively impacts the user experience.

Limit Logins to a Specified IP Address or Range :-

If you allow access only from a designated IP address or range, brute force attackers will need to work hard to overcome that obstacle and forcefully gain access. It is like placing a security perimeter around your most precious data, and everyone who doesn’t originate from the right IP address is not allowed access.

You can set this up by scoping a remote access port to a static IP address. If you don’t have a static IP address, you can configure a VPN instead. One downside is that this might not be appropriate for every use case.

Employ 2-Factor Authentication (2FA) :-

Two-factor authentication is considered by many the first line of defense against brute force attacks. Implementing such a solution greatly reduces the risk of a potential data breach.

The great thing about 2FA is that password alone is not enough. Even if an attacker cracks the password, they would have to have access to your smartphone or email client. Very persistent attackers might try to overcome that obstacle, but most will turn around and search for an easier target.

Use Unique Login URLs :-

Create unique login URLs for different user groups. This will not stop a brute force attack but introducing that additional variable will make things a little bit more difficult (think time-consuming) for the attacker.

Monitor Your Server Logs :-

Be sure to analyze your log files diligently. Admins know that log files are essential for maintaining a system.

Log management applications, such as Logwatch, can help you perform daily check-ups, and can auto-generate daily reports.

I hope you enjoyed this article.