What is a password spraying attack?

If you’re unsure of what password spraying is, it’s an attack strategy wherein a user’s account is attempted to be accessed using several or a dozen of the most popular passwords, such as 12345 or password123. Password spraying or password spray attack implies that by guessing a single password, attackers will gain access to several accounts for which it is used.

This tactic may seem relatively primitive. However, it works because many users utilize weak passwords across numerous accounts, making it simple for hackers to predict them.

Password spraying vs. brute force vs. password stuffing

At first glance, password spraying resembles two other tactics popular among threat actors: brute force and password stuffing. However, there are significant distinctions  between these tactics. Let’s explore what is the difference between brute forcing and password spraying.

The brute force tactic involves attempting to crack a password for a single account using automated software to try every possible combination of characters. This method is often used when the attacker has no information about the password, and it can be time-consuming and resource-intensive.

Password spraying, on the other hand, involves using a few passwords to gain access to multiple accounts. The passwords for such attacks may be found among commonly used passwords, bought on data leak websites or underground markets, or obtained through social engineering techniques.

This method is often used when the attacker has some information about the target, such as their email address or username. Password spraying can be more effective than brute forcing because it targets weak or reused passwords, which are common among users.

The answer to what is the difference between password spraying and password stuffing also lies in the details. Password stuffing involves trying many username and password combinations against multiple accounts. The attacker will use automated software to try username and password combinations, often obtained from previously leaked databases.

Are password spraying attacks common?

Password spraying is a popular tactic among cybercriminals because it can often be successful against users who reuse passwords across multiple accounts. These attacks are effective against organizations with weak password policies or do not use multi-factor authentication.

Many high-profile data breaches in recent years have resulted from password spraying attacks. For example, the 2018 Marriott data breach, which exposed the personal information of over 500 million customers, started with a password spraying attack.

How password spraying attacks affect business

The password spray attack method allows threat actors to access multiple accounts, which increases the chances of infiltrating corporate infrastructure and gaining unauthorized access to sensitive information or resources. Eventually, password spraying leads to such implications as data breaches, financial losses, and reputational damage.

Furthermore, password spraying attacks can be a stepping stone for more advanced attacks, such as spear phishing or malware attacks. Once an attacker gains access to one account, they may be able to use that access to launch more targeted attacks against other accounts or systems within the organization.

Password spraying attacks can be difficult to detect, as they do not trigger many security systems designed to detect brute force attacks. It means attackers can continue attempting to access accounts over a long period without being detected.

How to detect a password spraying attack?

Password spray attacks may be spotted through such indicators as an unusually high number of authentication attempts, especially the failed ones. If the attempts to log in come from a single IP address of the device, it’s a bulletproof sign of password spraying.

If you see login attempts from former employees or invalid usernames, it may also indicate a password spray attack. In this case, threat actors are probably using outdated credentials.

Eventually, any type of anomaly in the corporate network or other suspicious activity, such as unusual file transfers or changes to account settings, could indicate that an attacker has gained access to an account.

What can a business do to avoid password spraying attacks?

As we have already mentioned, a password spraying attack is a type of cyber attack that involves repeated attempts to use the same or similar passwords for different user accounts. To avoid this type of attack, it’s a good idea to implement some basic security practices:

  • Enforce strong password policies

Require employees to use strong, complex passwords that are difficult to guess. Passwords should be at least 12 characters long and include a mix of uppercase and lowercase letters, numbers, and symbols. Employees should also be encouraged to change their passwords regularly.

  • Implement multi-factor authentication 

Require employees to provide a second form of authentication, such as a code sent to their phone, in addition to their password. This can help prevent password spraying attacks by making it more difficult for attackers to gain unauthorized access.

Software manufacturers often release security patches that fix known security vulnerabilities. Timely implementation of such patches can lessen the number of weak spots in the infrastructure and prevent many security incidents.

  • Employ solutions for traffic monitoring

Traffic anomalies are often a sign of password spraying or other types of cyber attacks. Network traffic analysis tools can help identify unusual traffic, while network detection and response solutions provide an opportunity to spot and mitigate the attack at early stages.

Does Group-IB provide solutions to prevent or mitigate password spraying attacks?

Group-IB flagship Managed Detection and Response solution provides both network and endpoint protection, allowing you to detect anomalies in the network traffic and spot password spraying and other types of attacks on the host level. Our solution can identify the sophisticated threats that would otherwise go undetected.

In addition to attack detection, Group-IB Managed Detection and Response provides capabilities to stop adversaries in a single click. It allows isolating compromised hosts to block the ongoing attack, track adversaries’ steps, and conduct forensic investigations to prevent similar attacks.