Password spraying is a type of cyberattack that involves guessing passwords by using a few commonly used passwords against a large number of usernames or email addresses. Unlike targeted attacks, password spraying is a high-volume attack that’s not aimed at specific individuals or accounts.

The goal of password spraying is to exploit weak or easily guessable passwords that are commonly used by individuals within an organization or across different online platforms. This makes businesses that allow password sharing among employees extremely vulnerable.

Common targets of password spraying include cloud-based applications and services, email accounts, and remote access services. 

Password spraying has become increasingly common, with many high-profile companies falling victim to these attacks. According to the 2022 Microsoft Digital Defense Report, there has been a significant surge in password attacks. Over the past year, there has been a staggering 74% increase in the frequency of password attacks, with the attacks occurring at a rate of 921 per second.

How does password spraying work?

The steps involved in a password spraying attack typically include:

  • Selecting targets. Attackers identify their target, which can be a specific organization, a group of users, or a large-scale online service. Attackers typically use information that is publicly available or obtained through social engineering techniques, ​​public websites, or previously breached data.

  • Username enumeration. Using similar techniques to the ones listed above, the attackers then gather valid usernames associated with the target organization or service.

  • Compiling a list of common passwords. Attackers create a list of commonly used or easily guessable passwords. These passwords often include simple combinations, default passwords, common words, or variations of known passwords.

  • Attacking. The attackers use automated scripts or tools to systematically try each username from the previously generated list of usernames against a small set of passwords. Rather than trying numerous passwords for a single account, the attacker tries a few passwords on many accounts. This technique helps attackers avoid detection from account lockouts or excessive failed login attempts.

  • Compromising accounts. Once attackers have discovered a valid username-password combination, they can gain access to the compromised account to steal sensitive information or use the account for future attacks.

If you think password spraying techniques sound vaguely familiar, you’re not wrong. They do resemble common broken authentication attacks but have subtle differences.

Password spraying vs. brute force attack

A brute force attack uses automated tools to systematically try a vast number of possible passwords until the correct one is discovered.

In contrast to password spraying, a brute force attack targets a single account, rather than multiple accounts at once. Brute force attacks can be more effective than password spraying, but they are also more time-consuming and resource-intensive for attackers.

Characteristics

Password Spraying

Brute Force Attack

Attack Methodology

Tries a few passwords against multiple accounts

Tries all possible password combinations against a single account

Scope

Wide scope; multiple accounts targeted

Narrow scope; single account targeted

Resource Utilization

Limited number of passwords attempted against each account

Exhaustive trial of all possible password combinations

Time Efficiency

Can be relatively quick, especially with early success

Can be time-consuming, especially with strong passwords

Attack Detection

Harder to detect as it involves a limited number of passwords per account

Easier to detect due to high volume of failed login attempts

Password spraying vs. credential stuffing

Credential stuffing is another type of cyberattack that involves using stolen login credentials, such as usernames and passwords, to gain unauthorized access to accounts. Unlike password spraying, credential stuffing does not involve guessing passwords but instead relies on the use of stolen credentials.

Credential stuffing attacks are typically carried out using automated tools and can be highly effective, especially if the stolen credentials are from a high-profile data breach.

Characteristics

Password Spraying

Credential Stuffing

Attack Methodology

Tries a few passwords against multiple accounts

Tries stolen credentials against multiple platforms

Source of Credentials

Commonly used passwords or easily guessable variations

Stolen credentials from previous data breaches

Targeted Accounts

Specific organization, online service, or group of users

Multiple platforms or services

Detection and Mitigation

Challenging to detect; account lockouts, multi-factor authentication, strong password policies

Easier to detect; anomaly detection, rate limiting, behavioral analysis

Objective

Find valid username-password combinations within target scope

Gain unauthorized access to user accounts on a specific platform

How to prevent password spraying attacks

Preventing password spraying attacks typically requires a combination of best practices for password security and strategies to detect and mitigate these attacks. Preventive measures such as account lockouts, multi-factor authentication, and strong password policies can significantly mitigate the success of password spraying attacks.

Best practices for password security

  • Encourage users to create strong, unique passwords that include a combination of alphanumeric characters, special symbols, and are at least a certain length.

  • Discourage the use of easily guessable passwords, such as common words, sequential numbers, or personal information (e.g.  "password" or "123456").

  • Implement password expiration policies that require users to change their passwords regularly.

Strategies to prevent password spraying attacks

  • User education: Organizations should educate their users about the importance of using strong, unique passwords for each account. This can help users avoid common pitfalls and make their accounts less vulnerable to password spraying attacks.

  • IP blocking: Implement IP whitelisting to restrict access to systems only from trusted IP addresses. Also, consider implementing geolocation blocking to restrict access from certain high-risk countries or regions known for cybercriminal activities.

  • Limiting login attempts: Organizations can limit the number of login attempts that can be made within a certain time period. This helps prevent attackers from using automated tools to launch attacks by slowing down the rate at which they can make login attempts.

  • Anomaly detection: Implement security systems that can detect unusual login patterns and anomalous behavior. 

  • Multi-factor authentication: Multi-factor authentication (MFA) requires users to provide additional proof of identity beyond just a password. By requiring MFA, organizations make it much more difficult for attackers to gain unauthorized access to user accounts, even if they can guess the user's password.

  • Adopt passwordless authentication: Passwordless authentication eliminates the use of traditional passwords, reducing the potential for password-based attacks altogether. For example, biometric authentication methods such as facial recognition or fingerprint scanning forgo passwords altogether, rendering password spraying attacks moot. 

Tools and techniques to detect and mitigate password spraying attacks

Detecting and mitigating password spraying attacks can be done by implementing intrusion detection systems (IDS), security information and event management (SIEM) systems, anomaly detection algorithms, and threat intelligence feeds. 

These tools and techniques monitor login activities and network traffic, detect suspicious patterns of behavior, and provide real-time information about known malicious IP addresses or compromised credentials. This makes it possible to detect and block password spraying attempts and protect systems and user accounts from unauthorized access.

  • Intrusion Detection and Prevention Systems (IDPS): IDPS solutions can analyze network traffic, monitor login attempts, and detect patterns associated with password spraying attacks. They can raise alerts or automatically block suspicious activities.

  • Log Analysis and Monitoring: Regularly review logs of failed login attempts, analyze patterns, and look for anomalous login behavior indicative of password spraying attacks. Tools like SIEM (Security Information and Event Management) systems can help in log analysis.

  • User and Entity Behavior Analytics (UEBA): UEBA tools can establish a baseline of normal user behavior and detect deviations from that baseline. Unusual login patterns, such as multiple failed login attempts across different accounts, can indicate password spraying attacks.

Protect user accounts with Descope’s passwordless authentication

Password spraying attacks pose a serious threat to your organization and users. Implementing best practices for password security, monitoring for suspicious activity, and using threat intelligence feeds can help reduce the risk of a successful attack.

However, while these strategies and tools can help mitigate password spraying attacks, using passwordless authentication is perhaps the best way to protect against password spraying and cyber theft altogether.

Descope’s passwordless authentication significantly reduces the attack surface for your app or website. It also eliminates the risk of weak or compromised passwords, which is the primary vulnerability that password spraying attacks exploit. 

Descope helps developers add secure, frictionless authentication to their apps, providing their end users with delightful login experiences that do not rely on passwords.

Sign up for Descope and start your app’s passwordless journey.