· Alex · security  · 11 min read

Password Spraying

Definition, tools, and defenses against password spraying attacks

Definition, tools, and defenses against password spraying attacks

What is Password Spraying

Definition of password spraying

Password spraying is a technique where actors target multiple user accounts by attempting a few commonly used passwords on each account. This approach is stealthy and evades account lockout policies because it doesn’t exceed the allowed number of failed login attempts for a single account. The attackers can then patiently cycle through a list of common passwords, hoping to eventually gain access to one or more accounts.

How it differs from other password attacks (brute force, dictionary attack)

  1. Brute force attack: In a brute force attack, the attacker systematically tries every possible password combination on a single account until the correct password is found. This method can be time-consuming and is more likely to trigger account lockout policies, making it easier to detect.
  2. Dictionary attack: A dictionary attack is similar to a brute force attack, but instead of trying every possible combination, the attacker uses a list of words or phrases (typically from a dictionary or other word source) to guess the password. This can be faster than a brute force attack but still focuses on a single account and may trigger lockout policies.

Password spraying, on the other hand, targets multiple accounts with a smaller number of password attempts, making it a more stealthy and challenging attack to detect and prevent.

Common tools and techniques used in password spraying attacks

  1. Hydra: Hydra is a well-known password-cracking tool that supports various protocols and can be used for password spraying.
  2. Metasploit: The Metasploit Framework is a powerful penetration testing tool that includes modules for conducting password spraying attacks.
  3. PowerShell scripts: Attackers often use custom PowerShell scripts to automate password spraying. One such example is the “Invoke-PasswordSpray” script, which simplifies the password spraying process for Windows-based systems.
  4. Custom tools: Sophisticated attackers may develop their own custom tools for carrying out password spraying attacks tailored to their specific targets.

When it comes to techniques, attackers often rely on open-source intelligence (OSINT) to gather information about their targets, such as email addresses and usernames. They’ll also carefully select their list of common passwords, sometimes tailoring it to the target organization or industry to increase their chances of success.

Real-World Examples of Password Spraying

Notable incidents involving password spraying

Password spraying may sound like a simple technique, but it’s been behind some high-profile cyber incidents that had significant consequences. Password spraying has been used against big companies like Microsoft and even US government agencies.

Consequences of successful password spraying attacks

  • Data breaches
  • Ransomware attacks
  • Disruption of services
  • Reputational damage

Why Password Spraying Works

The psychology of password creation

Password spraying attacks are successful mainly because of human psychology and the way we create passwords. Often, people choose passwords that are easy to remember, which unfortunately means they can be easy to guess as well. Factors that contribute to this include:

  1. Familiarity: Users tend to create passwords based on familiar words, phrases, or patterns, such as their pet’s name, favorite sports team, or a simple sequence of numbers.
  2. Cognitive biases: People tend to underestimate the likelihood of being targeted by hackers, leading to a false sense of security when it comes to password strength.
  3. Convenience: Many users prioritize convenience over security, opting for simple passwords that can be easily remembered and typed.

Common weak passwords

Attackers often use lists of known weak passwords in their password spraying attempts. These lists include passwords that are commonly used or can be easily guessed. Some examples include:

  1. Basic number sequences: Passwords like “123456” or “111111” are easy to remember but offer little security.
  2. Common words and phrases: Words like “password,” “qwerty,” or “letmein” are frequently used as passwords and are well-known to attackers.
  3. Personal information: Dates of birth, anniversaries, and names of family members or pets can be easily discovered through social media and other online sources, making them poor choices for passwords.

User habits that contribute to password spraying vulnerability

  1. Password reuse: Many users reuse the same password across multiple accounts, which can make it easier for attackers to gain access to multiple systems or services if they manage to crack one password.
  2. Infrequent password changes: Failing to change passwords when they are compromised or published in a breach increases the risk of a password being discovered and used in a password spraying attack. NIST SP800-63B recommends that services must not require periodic password changes. It wasn’t always like this. The reason for the change is that users tend to apply an easy transformation to their password when changing is requested periodically. Consider a password like “SuperS3crTP4SS1”. If there’s a yearly password change requirement, there’s a big chance that the user would change it to “SuperS3crTP4SS11” or “SuperS3crTP4SS2”, etc. This makes the password easy to guess using more advanced cracking techniques that use various mutation rules.
  3. Sharing passwords: Sharing passwords with colleagues, friends, or family members can increase the likelihood of a password being leaked or discovered by attackers.

How to Detect Password Spraying Attacks

Signs of a password spraying attack

  1. Multiple failed login attempts: If you notice multiple failed login attempts from different accounts within a short time frame, it could be an indication of a password spraying attack.
  2. Unusual login patterns: Password spraying attacks may involve login attempts at odd hours or from unfamiliar geographic locations, which can be detected by monitoring and analyzing login data.
  3. Anomalous network traffic: If you see unusual spikes in network traffic, particularly from IP addresses or regions not typically associated with your user base, it could be a sign of a password spraying attack in progress.

Monitoring tools and techniques to detect password spraying

There are various tools and techniques that can help organizations detect password spraying attacks:

  1. Security Information and Event Management (SIEM) systems: SIEM solutions can collect, analyze, and correlate security events from various sources, helping to identify patterns that may indicate a password spraying attack.
  2. Log analysis: Regularly reviewing and analyzing logs from authentication systems, firewalls, and intrusion detection/prevention systems can help identify signs of password spraying attacks.
  3. User and Entity Behavior Analytics (UEBA): UEBA solutions use machine learning and artificial intelligence to analyze user behavior and identify unusual patterns that may suggest a password spraying attack.
  4. Account lockout policies: Implementing and monitoring account lockout policies can help detect password spraying attempts, as multiple failed login attempts within a certain time frame can trigger an alert.

The role of security teams in detecting and responding to attacks

Security teams play a crucial role in detecting and responding to password spraying attacks. Some key responsibilities include:

  1. Establishing monitoring and detection capabilities: Security teams should implement the appropriate tools and processes to monitor for password spraying attacks, including SIEM systems, log analysis, and UEBA solutions.
  2. Conducting regular threat hunting: Proactively searching for signs of password spraying attacks in logs and other data sources can help security teams identify and respond to attacks before they cause significant damage.
  3. Responding to incidents: In the event of a detected password spraying attack, security teams should act quickly to contain the threat, investigate the scope of the compromise, and implement measures to prevent future attacks.
  4. Educating users: Security teams should work closely with users to raise awareness about password spraying attacks and promote good password hygiene, helping to reduce the organization’s overall risk.

Best Practices to Defend Against Password Spraying

Strong password policies and enforcement

To protect against password spraying attacks, organizations should implement and enforce robust password policies:

  1. Complexity requirements: Passwords should contain a mix of uppercase and lowercase letters, numbers, and special characters to make them more difficult to guess.
  2. Length requirements: Longer passwords are generally more secure, so organizations should require a minimum password length, typically at least 12 characters.

Multi-factor authentication (MFA)

  1. Different types of MFA: MFA can take several forms, including hardware tokens, software tokens, or mobile apps that generate one-time passcodes, biometric authentication (e.g., fingerprint or facial recognition), or push notifications.
  2. The benefits of MFA in preventing password spraying: Even if an attacker successfully guesses a password, MFA can prevent unauthorized access by requiring additional authentication factors. This significantly reduces the risk of successful password spraying attacks.

User education and awareness

  1. Importance of ongoing cybersecurity training: Organizations should provide regular cybersecurity training to educate users about password spraying and other threats. This training should include guidance on creating strong, unique passwords and the importance of not reusing passwords across multiple accounts.
  2. Addressing the human factor in password security: Security awareness campaigns should emphasize the role that each user plays in protecting the organization from password spraying attacks.

Advanced Defense Techniques

Artificial intelligence and machine learning in cybersecurity

AI and machine learning can be powerful tools for enhancing an organization’s cybersecurity posture:

  1. Real-time threat detection: AI-driven security solutions can analyze vast amounts of data in real-time, identifying threats and alerting security teams to potential password spraying attacks.
  2. Adaptive authentication: Machine learning algorithms can assess the risk level of login attempts based on various factors, such as the user’s behavior, device, and location. High-risk attempts can be subjected to additional authentication challenges, reducing the chance of unauthorized access.
  3. Predictive analytics: AI and machine learning can help organizations predict and proactively address potential security threats by analyzing patterns and trends in their network data.

Behavioral analytics for detecting anomalous login patterns

Behavioral analytics can be an effective method for detecting password spraying attacks by monitoring and analyzing user behavior:

  1. Baseline behavior: Security solutions can establish a baseline of normal user behavior, making it easier to identify deviations that could indicate a password spraying attack.
  2. Risk scoring: By assigning a risk score to each login attempt based on factors such as time, location, and the user’s typical behavior, organizations can identify suspicious activity and take appropriate action.
  3. Automated response: When behavioral analytics detects a potential password spraying attack, automated response mechanisms can be triggered, such as locking accounts, sending alerts, or initiating additional authentication steps.

Deceptive techniques, such as honeypots and honey accounts

Deceptive techniques can help organizations detect and thwart password spraying attacks by luring attackers into revealing their tactics:

  1. Honeypots: A honeypot is a decoy system or network resource designed to attract attackers, allowing security teams to monitor their activities and gain insight into their tactics.
  2. Honey accounts: Honey accounts are fake user accounts created specifically to detect password spraying attacks. These accounts are designed to appear legitimate but have no real purpose within the organization. If an attacker attempts to access a honey account, it serves as a strong indicator of a password spraying attack in progress.

The Future of Password Security and Authentication

Emerging authentication technologies

Several new technologies and authentication methods have the potential to revolutionize how we secure our digital identities:

  1. Risk-based authentication: This approach adjusts the level of authentication required based on the risk associated with a specific login attempt, considering factors like user behavior, device, and location.
  2. Fast Identity Online (FIDO) standards: FIDO is a set of open standards that enable simpler, stronger authentication across various devices and services, without the need for traditional passwords.
  3. Decentralized identity: Decentralized identity solutions aim to put users in control of their own digital identities, using blockchain and other distributed ledger technologies to provide secure, private, and interoperable identity management.

The potential impact of biometrics and other innovations

Biometrics and other innovative technologies have the potential to reshape password security and authentication:

  1. Biometric authentication: Biometric methods, such as fingerprint, facial, or iris recognition, provide a more secure and user-friendly alternative to traditional passwords.
  2. Continuous authentication: Technologies like keystroke dynamics, gait analysis, or heart rate monitoring can provide ongoing authentication by continuously verifying a user’s identity, even after the initial login.

Moving towards a passwordless future

The ultimate goal for many security experts is to move towards a passwordless future, where users no longer need to rely on traditional passwords for authentication:

  1. Passwordless authentication methods: Techniques like single sign-on (SSO), mobile push notifications, or hardware tokens can provide secure authentication without the need for users to remember and enter passwords.
  2. User experience and security: Passwordless authentication methods can offer both improved user experience and enhanced security, reducing the likelihood of successful password-based attacks like password spraying.
  3. Adoption challenges: Despite the potential benefits of passwordless authentication, widespread adoption may take time as organizations face challenges related to legacy systems, user behavior, and the need to balance security with usability.

Conclusion

As hackers continue to evolve their tactics and exploit human weaknesses in password creation and management, password spraying remains an ongoing threat for organizations and individuals alike. The stealthy nature of these attacks makes them difficult to detect and prevent, emphasizing the importance of staying vigilant and adopting proactive defense measures.

In conclusion, understanding and defending against password spraying attacks require a multifaceted approach, encompassing strong password policies, advanced security tools, user education, and the adoption of emerging authentication technologies.

About the Author:

Alex

Application Security Engineer and Red-Teamer. Over 15 years of experience in Application Security, Software Engineering and Offensive Security. OSCE3 & OSCP Certified. CTF nerd.

Back to Blog

Related Posts

View All Posts »
My OSCP Journey

My OSCP Journey

Common questions, my experience, preparation and methodology as well as tips to help you land the OSCP exam