In the world of web security, one of the most common and oldest intrusion methods is Brute Force attacks, also known as omnipresent search attacks. In this type of attack, hackers use scripts and bots to attempt to guess the username and password of various systems, websites, or services, thereby gaining complete control by logging in. Unlike other more complex intrusion methods, Brute Force is a simple but very effective attack, especially when users use weak or repetitive passwords.
In this article, we will examine how a brute-force attack works, its various types, the dangers it poses to CMS-based sites like WordPress, and the available solutions to combat it.
What is a brute-force attack? A closer look at the nature of the threat
The word “Brute Force” in English means “physical force” or “brute power”. In the world of cybersecurity, this term is also used to describe attacks in which an attacker attempts to penetrate a target system by repeatedly attempting to guess the password or login key, without exploiting software vulnerabilities.
In this type of attack, the hacker uses an extensive list of common passwords (or random combinations of letters and numbers) and attempts to log in to the system using each one on the login form. The speed and number of these attempts depend on the type of script, the power of the attacker’s server, and the security limitations of the target server.
Different Types of Brute Force Attacks
Although the general concept of Brute Force is simple, this attack can be carried out in different ways, the most important of which are discussed below:
Classic Brute Force Attack (Traditional)
In this method, the hacker tries to guess the password by trying all possible combinations of characters. This type of attack can be time-consuming, but if the password is short and simple, it is almost certain to succeed.
Dictionary Attack
In a dictionary attack, the attacker uses a file containing millions of common passwords (e.g., 123456, “password”, “admin”, “qwerty”). This method is faster than traditional Brute Force and, in many cases, is successful because many users use weak passwords.
Credential Stuffing Attack
In this type of attack, the hacker uses usernames and passwords that have already been leaked on other sites. Since many users use the same password for multiple accounts, this method is especially dangerous and effective.
Reverse Brute Force Attack
In this method, the attacker tries a specific password (e.g., 123456) against a list of different usernames. This model is used to penetrate systems with multiple users.
What is the goal of attackers in Brute Force attacks?
The primary objective of Brute Force attacks is to access confidential information or gain complete control over a service. However, depending on the type of target system, this access can take various forms:
- Logging into the site’s administration panel (for example, /wp-admin in WordPress)
- Infiltrating the email service or hosting
- Accessing SSH or the server’s control panel
- Making destructive changes or injecting malware
- Using system resources to mine cryptocurrency or launch further attacks (Botnet)
Why are CMSs like WordPress more vulnerable to Brute Force attacks?
Content management systems like WordPress, Joomla, or Drupal are often popular targets for attackers due to their standard login addresses (such as /wp-login.php or /administrator). Once a hacker knows that the path to the administration panel is the same, all he has to do is run a script on that path.
Additionally, many WordPress users do not change the default username, “admin,” and often use simple passwords. This makes it easier for brute-force attacks to occur.
Prevent Brute Force Attacks in WordPress
WordPress is one of the main targets for Brute Force attacks due to its high popularity and well-known default structure. The default login path for most WordPress sites is wp-login.php or wp-admin/, which makes it easy for bots to identify the attack point.
To secure your WordPress site against these attacks, the following steps are recommended:
- Change the login path to the dashboard: Using plugins like WPS Hide Login, you can change the login path from wp-login.php to an unguessable address. This method is one of the simplest but most effective ways to block bots.
- Limit the number of failed login attempts: Plugins like Limit Login Attempts Reloaded or Loginizer allow you to control the number of incorrect login attempts and temporarily block the attacker’s IP after a certain number of errors.
- Enable Two-Factor Authentication (2FA): With plugins like Wordfence or Google Authenticator, you can rely on a second factor, such as a one-time code, in addition to your password. This feature significantly increases security.
- Use CAPTCHA in your login form: Adding Google reCAPTCHA to your login page makes it difficult for bots to submit requests easily.
- Use comprehensive security plugins: Plugins like iThemes Security, Wordfence, or All in One WP Security offer a variety of tools to combat Brute Force Attacks, including monitoring logins, locking out suspicious users, and identifying attacker IPs.
These measures may seem simple, but if implemented correctly, they can protect your WordPress site from a large wave of automated brute-force attacks.
Read More: What is a Hybrid Server?
How to prevent Brute Force attacks?
There are various solutions to combat Brute Force attacks, which can be classified into two levels of structural prevention and increasing the resistance of the entry point. Here are some important and effective solutions:
Use a strong and complex password
The first and easiest way to combat a brute-force attack is to choose long, unpredictable passwords and a combination of uppercase and lowercase letters, numbers, and symbols. Tools like Password Manager help you generate and store secure passwords.
Limit the number of login attempts.s
You can limit the number of unsuccessful login attempts by using plugins like Limit Login Attempts in WordPress or your server’s firewall settings. For example, if a user enters the password incorrectly 5 times, their access will be blocked for a few minutes or even hours.
Enable two-factor authentication (2FA)
By enabling two-factor authentication, even if the password is guessed correctly by the attacker, it will not be possible to log in without a secondary verification code (usually sent to a mobile phone or email).
Change the default login path.
In systems like WordPress, plugins such as WPS Hide Login can redirect the /wp-login.php address to a desired path. This makes it difficult for attackers’ automated scripts to find the login path easily.
Use a firewall and security tools.
Activating firewalls like CSF, Fail2Ban, Imunify360, or using cloud security services like Cloudflare can detect and block Brute Force attacks at the network level, even before they reach the code execution stage.
Signs of a Brute Force Attack
Suppose you notice that your site has suddenly slowed down, server resources are being used up unusually, or your system logs are full of failed login attempts from various IP addresses. In that case, there is a high chance that you are experiencing a Brute Force attack. Carefully reviewing your server log files and activating security alerts can be an effective way to detect these attacks quickly.
Summary: A simple but very dangerous attack
Despite their simplicity, Brute Force attacks are one of the most common security threats to sites and servers. In many cases, just ignoring the password or using the default configuration can easily expose the site to intrusion.
By following simple yet key tips, such as choosing a strong password, limiting the number of logins, enabling two-factor authentication (2FA), and utilizing security tools, you can easily become resistant to this type of attack and significantly increase the security of your site.