Understanding Brute Force Attacks and How to Stop Them in Their Tracks

A brute force attack is a method of hacking that attempts to break into a network or computer system by trying out every possible password combination until the right one is found. Brute force attacks are often used by malicious actors to break into websites or computer systems. These attacks rely on the fact that most internet users select easy-to-guess passwords, like “123456” or “password.” Since these passwords are easy to guess, an automated brute force attack can quickly break into a system using a single computer. This is why brute force attacks are often used for denial-of-service (DoS) attacks, where hackers use a botnet to try every possible username and password combination until one works. Brute force attacks are also used in distributed denial-of-service (DDoS) attacks, whereby hackers try to overwhelm a system with traffic until it crashes.

So what makes brute force attacks so dangerous? Let’s take a look at some stats to understand. 

Over 80% of hacking breaches use brute force or credentials that have been lost or stolen. Moreover, research from Google Cloud shows that brute-force attacks still represent the vast majority of threats to cloud service providers, making up 51% of all attacks in the first quarter of 2022. 

Brute force attacks are especially dangerous because they can try thousands upon thousands of combinations. Once they find a single correct combination, they can easily break into a network and wreak havoc. Brute force attacks remain one of the most common types of cyberattacks today. 

Like most cyberattacks, the motives behind a brute force attack vary from one hacker to the next. Some hackers do it for fun, just because they can. Some do it for political reasons. Some do it for money. Listed below are a few examples:

• Steal sensitive, personal data through phishing attacks
• Seek revenge against your business by disrupting its operations or damaging its assets
• Track user browsing data and sell it to third parties or other criminals
• Infect your system with malware and take over your system
• Insert ads into your website and profit from them
• Break into directories or web pages that would otherwise be inaccessible to the public
• Escalate privileges and launch bigger attacks
• Disable websites
• Redirect website traffic to paid advertising sites

Brute force attacks rely on cracking passwords with repeated trial and error attempts. There are a number of ways to do this but usually hackers use automated tools or software to execute these attacks. They can also purchase pre-built, ready-to-use password cracking software or malware kits that are available on the dark web. In addition to ready-made kits, lists of stolen credentials are also available on the dark web for attackers to use. 

Botnets and bots are also commonly used to carry out brute force attacks. Botnets are infected zombie computers that are most commonly used to carry out denial of service attacks, but attackers leverage these computers to brute force passwords as well.

Once hackers have a foothold inside a system, they can do just about anything they want. They can steal sensitive information, hold the system hostage, or even delete important data. Because they have a computer on the inside, they have the power to do anything they want.

Types of Brute Force Attacks

Brute force attacks are categorized in three different ways by different organizations. We’re going to look at the following types of brute force attack types:

Dictionary Attacks

In a dictionary attack, the attacker uses a combination of popular words and phrases to guess passwords. In addition to using a combination of numbers and words from the dictionary to guess passwords, these attacks also use passwords that have been leaked previously in other data breaches. Attackers use dictionary software that allows them to generate thousands of passwords using different combinations of words and characters. 

Simple Brute Force Attacks

Simple brute force attacks are the most basic type of brute force attack and involve the attacker guessing numerous passwords while targeting a specific list of usernames. They keep doing this until they come up with a combination that works. Quite often, the attacker will rotate through a huge list of password guesses while focusing on specific usernames. Since the attacker has to generate every possible set of letters, numbers, and special characters, it becomes a time-consuming and tedious process. As a result, it works well for shorter passwords but makes it difficult to guess longer ones.

Reverse Brute Force Attacks

In a simple or traditional brute force attack, the attacker starts off with a known identifier such as an account number or a username. They then use tools and techniques to figure out the password to that account. In a reverse brute force attack, the attacker starts off with the password and must locate the matching username or account number. 

Hybrid Brute Force Attacks

Hybrid brute force attacks combine features of both simple brute force attacks and dictionary attacks. To build a larger database of password combinations to try, attackers combine common passwords with dictionary words and random characters. 

Credential Stuffing

In a credential stuffing attack, attackers will use stolen credentials across many different websites. This is because people have the tendency to reuse passwords for different accounts. So once the attacker has the password for one account, there is a good chance they'll get a hold of a list of other accounts that are using the same password.