Published
Last Updated

Brute Force Cyberattacks Explained

Brute force attacks are a type of cyberattack in which the adversary tries every possible combination of passwords, login credentials, or encryption keys until they gain access. They are called "brute force" because little finesse is used in these attacks. Instead, they spam login attempts until they gain access, logging in by sheer will and chance.

Common brute force attacks involve using bots and programs to swiftly attempt every possible username and password combination until access is gained. Attackers can also manually guess passwords, preying on users with weak password etiquette in hopes of quickly cracking the code.

Since the early days of computing, brute force attacks have been a prevalent cyberattack method. They began as simple attacks but have evolved alongside computer technology to become more and more sophisticated. Today, brute force attacks are among the most common types of cyberattacks.

Types of Brute Force Attacks

Several types of brute force attacks exist, including simple and advanced methodologies. These include:

Simple Brute Force Attacks

  • This occurs when attacks manually guess password combinations or PIN codes based on common, weak trends (e.g., password123 or 1234). They work because many users still use weak passwords or exhibit poor password practices, such as using the same password for several websites.

Dictionary Attacks

  • These attacks can take a lot of time to be successful and have a low success rate overall, but they are a key step in the password-cracking journey. Although they are not considered full-blown brute force attacks, dictionary attacks involve running through a dictionary to identify common words and tweak them with special characters and numbers.

Hybrid Brute Force Attacks

  • Attackers blend simple brute force attacks with dictionary attacks, beginning with a known username. The hacker then guesses passwords for that username based on common words and modifications to words combined with easy numerical combinations, such as years, to gain access.

Credential Stuffing

  • This attack type thrives on users using the same username and password combinations across multiple websites. When an adversary collects a username and password, they stuff that credential combination into other sites, hoping to gain access thanks to a user's weak password etiquette.

Reverse Brute Force Attacks

  • A reverse brute force attack begins with a password, which is then tested against potential usernames that leverage that password. These passwords are typically gained through a network breach. If weak passwords are discovered, they can be tested against several different usernames to expand access further.

Signs of a Brute Force Attack

There are several telltale signs that a brute force attack has occurred. First, unusual account activity is a key indicator that it has been compromised. This unusual activity can include changes to settings, attempted password updates, unauthorized posting, and more.

Multiple login attempts are another sign of attempted compromise. Many websites will alert users via email if too many unsuccessful attempts have been made to log in. If these emails are received, it is a sign that someone is trying to access your account, and credentials should be updated.

Finally, network performance issues can be a sign of enterprise account compromise. If network traffic has increased or strange things are happening across the network, such as the export of sensitive information, then it is likely that an adversary is working to obtain valuable information that can be used for nefarious purposes.

Preventing Brute Force Attacks

Brute force attacks are common but can be prevented with simple measures. Here are 3 simple steps that can be taken to secure accounts:

  1. Strong Passwords are significantly more difficult to crack, making them the most effective way to prevent brute force attacks. Strong passwords do not use personal information or easy-to-guess words but are rememberable for the user. Ideally, users should use different passwords for each account. Random character strings, longer than 6 characters and ideally at least 15 characters, are suggested as they are harder to crack than dictionary words.
  2. Two-Factor Authentication (2FA) requires a second step to gain access to an account. With 2FA, users must verify their identity by providing a secondary action, such as approving the login on a mobile device or entering a secondary verification code, to prevent unauthorized access to accounts.
  3. CAPTCHAs are another common practice for account security that organizations can implement. These are difficult for computer programs to complete, so if a hacker is using an automated program to crack passwords, they can be stopped in their tracks with a CAPTCHA.

The Truth Behind Brute Force Attacks

Brute force attacks are common but preventable with simple security measures. Ensuring 2FA and/or CAPTCHAs back strong passwords can provide a stout layer of defense against adversaries gaining access to accounts or devices. As attacker methodologies evolve, so must defenses and password complexity to prevent unauthorized access to accounts.