We tend to imagine hackers as brilliant masterminds playing three-dimensional chess, but the reality is, some of them still come wielding old-school digital sledgehammers instead of brilliantly crafted, next-level hacking tools.
Although it is true that some of today's most audacious hacks involve highly sophisticated techniques – the SolarWinds hack certainly did – brute force attacks are still incredibly common. In fact, they've been making a comeback since working from home became so commonplace.
Here's what a brute force attack is, why cyber criminals still use this blunt instrument, and how you can protect your business against it.
Understanding Brute Force Attacks
Definition of a brute force attack
One of the most common and straightforward forms of cyberattacks, brute force attacks involve an attacker systematically trying every possible combination of characters to guess a password, encryption key, or login credentials. Despite being a relatively simple technique, brute force attacks can be incredibly effective, especially against systems with weak security measures.
A brute force attack is a trial-and-error method used to decode encrypted data, such as passwords or PINs, by systematically attempting all possible combinations until the correct one is found. This type of attack relies on the sheer computing power available to hackers, who use automated software to run through millions of possible passwords in seconds.
Brute force attacks exploit the fact that many users choose weak passwords or reuse passwords across multiple accounts. This makes it easier for attackers to gain unauthorized access to systems, networks, and personal data.
How brute force attacks work
In a brute force attack, a hacker uses a simple automated tool to try and guess a username and password that will grant access to a company's website or app (or, in some cases, an encrypted file). This tool typically pelts the target with endless combinations of usernames and passwords until it lands on one that works. Once the hacker has access to that system, they can use that foothold to start poking around in the victim's network, find juicy resources to exploit, or plant some dangerous malware. Although this method takes time and computing resources, it can and does work – which is why it's still around today.
Brute force attacks are relatively easy to understand. They involve repeated attempts to log into an account or decrypt a file by trying different combinations of characters until the correct one is discovered. The effectiveness of these attacks depends on the strength of the password and the speed at which the attacker can generate guesses.
For example, an attacker might use a script that automatically generates password guesses, starting with "123456" and progressing to more complex combinations. Modern brute force attack tools can attempt millions of combinations in just a few minutes, making short or simple passwords particularly vulnerable.
Some advanced brute force attacks use distributed networks of computers, known as botnets, to increase the speed and volume of their attacks. These botnets can coordinate efforts across thousands of devices, making brute force attacks more powerful and harder to stop.
Common targets of brute force attacks
Brute force attacks can target a wide range of systems and accounts, but they are especially effective against user accounts, administrative accounts, encrypted data, and web applications. Common targets include:
- User Accounts: Personal accounts with weak passwords are prime targets for brute force attacks. This includes email accounts, social media profiles, and online banking accounts.
- Administrative Accounts: These accounts often have higher privileges and access to sensitive information, making them attractive targets for attackers.
- Encrypted Data: Attackers may attempt to decrypt sensitive data, such as files or databases, by brute-forcing the encryption key.
- Web Applications: Websites and online services are frequently targeted, especially those with weak login security or outdated software.
By targeting these systems, attackers aim to gain unauthorized access, steal data, or disrupt services.
How do Brute Force Attacks Work?
Motives of brute force attacks
Attackers may use brute force attacks for a variety of reasons. Some of the most common motives include:
- Data Theft: Attackers may seek to steal sensitive information, such as credit card details, personal identification numbers (PINs), or login credentials.
- Account Takeover: Gaining control of an account allows attackers to impersonate the victim, access private communications, or use the account for further malicious activities.
- Financial Gain: Some attackers use brute force attacks to gain access to financial accounts or e-commerce platforms, allowing them to steal money or make unauthorized purchases.
- Espionage: In some cases, brute force attacks are used to gain access to corporate or government systems, allowing attackers to steal confidential information or disrupt operations.
- Ransomware Deployment: By gaining access to a system, attackers can deploy ransomware, encrypting the victim’s data and demanding payment for its release.
Attackers can use brute force attacks to achieve a variety of goals. If a hacker is experienced, they will probably try to move laterally within the network to see what's available and worth exploring, performing a silent inventory of resources to potentially exploit when the moment is right.
If they're newbies or just feeling cocky, they may simply want to mess around with the victim's website or app to get attention or impress other novice hackers.
A bad actor may want to steal information that they can use to commit fraud or simply sell on the dark web for a tidy sum. They could also pillage business data and threaten to publish it in a data breach, demanding a hefty ransom for its return. The attacker could just install some nasty malware if they want. Or, they may have even darker aims – such as using the compromised system to stage larger and more damaging attacks on the target or even another organization.
Unless and until they're detected, the hacker may well have the run of the place. Instead of racing to spot them in time and then deal with the damage they've done, it's better to keep them from finding a way in.
Tools used in brute force attacks
Several tools are commonly used in brute force attacks, including automated software like Hydra, John the Ripper, and Aircrack-ng. These tools can systematically try millions of password combinations at high speed, significantly increasing the chances of a successful attack.
Types of Brute Force Attacks
There are a few different versions of the brute force attack.
Dictionary attacks
A dictionary attack literally throws the book at you, deploying every word in the dictionary along with some numbers and characters in an attempt to guess a password that will work for a specific account. This is a type of brute force attack where the attacker uses a list of common words and phrases, known as a dictionary, to guess the password. This method is faster than trying all possible combinations because it focuses on the most likely passwords.
Hybrid attacks
A hybrid brute force attack is a blend of the dictionary attack and a simple brute force attack. In this scenario, a hacker already knows a username and carries out a dictionary attack along with standard brute force techniques to figure out the password. Hybrid attacks combine a dictionary attack with a brute force attack by appending or prepending characters to words in the dictionary. For example, it might try "password1" after trying "password."
Credential stuffing attacks
Credential stuffing involves using a list of previously stolen usernames and passwords, trying them on different websites, and hoping that people have reused the same passwords across multiple sites.
Reverse brute force attacks
In a reverse brute force attack, the attacker knows the password but needs to figure out the username. The attacker systematically tries a list of usernames until they find the right match.
The Impact of Brute Force Attacks on Security
Potential consequences of successful attacks
If a brute force attack is successful, the consequences can be severe. The attacker could gain unauthorized access to sensitive information, financial accounts, or control over entire systems, leading to data breaches, financial loss, and reputational damage.
Protecting sensitive data from brute force attacks
To protect sensitive data from brute force attacks, it's crucial to use strong, unique passwords that are difficult to guess. Implementing account lockout policies, where an account is temporarily locked after a certain number of failed login attempts, can also help prevent these attacks.
The role of encryption in preventing brute force attacks
Encryption plays a critical role in protecting data from brute force attacks. Even if an attacker manages to obtain encrypted data, without the correct encryption key, the data remains inaccessible. Strong encryption algorithms make brute force attacks infeasible by requiring an impractical amount of time and resources to break the encryption.
Detecting and Preventing Brute Force Attacks
Signs of a brute force attack
Signs of a brute force attack include multiple failed login attempts in a short period, unusual IP addresses attempting to access the system, and a sudden spike in login traffic.
Implementing strong password policies
Strong password policies require users to create complex passwords that include a mix of letters, numbers, and special characters. Regularly updating passwords and avoiding password reuse across different sites can significantly reduce the risk of brute force attacks.
Using multi-factor authentication
Multi-factor authentication (MFA) adds an additional layer of security by requiring a second form of verification beyond just the password. This could be a code sent to the user's phone, a fingerprint scan, or another form of identity verification.
Best Practices for Brute Force Attack Prevention
Regularly updating software and security patches
Regularly updating software and applying security patches is essential to protect against vulnerabilities that could be exploited in brute force attacks. Many attacks take advantage of outdated software with known vulnerabilities.
Limiting login attempts
Limiting the number of login attempts before an account is locked is a simple but effective way to thwart brute force attacks. This measure can slow down or stop an attacker by preventing them from trying unlimited combinations.
Monitoring and analyzing system logs
Monitoring system logs for unusual activity, such as multiple failed login attempts, can help detect brute force attacks early. Regular log analysis can identify patterns that indicate an ongoing attack.
Using password management software
Password management software helps users create and store strong, unique passwords for each account. By using a password manager, individuals can avoid the need to remember complex passwords while significantly improving their security posture.
LastPass: Securing Your Passwords
Introduction to LastPass
LastPass is a password manager that helps users securely store and manage their passwords. With LastPass, users can generate strong, unique passwords for each of their accounts, reducing the risk of brute force attacks.
How LastPass protects against brute force attacks
LastPass protects against brute force attacks by storing passwords in an encrypted vault. Even if an attacker were to gain access to the vault, they would still need to break the encryption, which is practically impossible with today's technology.
Additional security features provided by LastPass
In addition to password management, LastPass offers features like multi-factor authentication, password strength analysis, and secure sharing options. These features add layers of security that make it even harder for attackers to succeed in brute force attacks.
