Password spraying is a stealthy and effective form of brute-force cyberattack that targets multiple user accounts using a small list of commonly used passwords. Rather than trying hundreds of password combinations on a single account—an approach that would trigger account lockouts—attackers "spray" a few common passwords across many accounts to fly under the radar.
This technique preys on a persistent weak spot in cybersecurity: human password habits. In this article, we will break down how password spraying works, how it differs from other brute-force attacks, and what steps organizations can take to detect and prevent it. We will also look at real-world examples and strategies to strengthen your defenses.
What Is Password Spraying and How Does It Work?
Password spraying is a type of brute-force attack where the attacker attempts to log into multiple user accounts using a small set of weak, commonly used passwords. By doing this, attackers can avoid triggering account lockout mechanisms, which typically activate after multiple failed login attempts on a single account.
Here is how the attack typically unfolds:
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Attackers obtain a list of valid usernames—often through data breaches, social engineering, or public sources like company directories.
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They automate login attempts across these accounts using a few commonly used passwords (e.g., Password123, Welcome1, Spring2025!).
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These attempts are often spread out over time to avoid detection.
The goal is to compromise at least one account without alerting security systems. Because the attack is slow and distributed, it often slips past basic monitoring tools and lockout protections.
How Password Spraying Differs from Other Brute-Force Attacks
Unlike traditional brute-force attacks that bombard a single account with many password guesses, password spraying flips the approach. It uses one password across many accounts, sidestepping lockout protections and blending in with normal login activity.
Brute-Force Attacks
Brute-force attacks involve repeatedly trying password combinations on a single account. These are noisy, resource-intensive, and relatively easy to detect due to high volumes of login attempts from a single source.
Credential Stuffing
Credential stuffing uses lists of stolen username/password pairs—usually from past data breaches—to gain unauthorized access. While credential stuffing relies on real credentials, password spraying guesses common passwords that users are likely to reuse.
Why Spraying Is Harder to Detect
Password spraying is stealthier because login attempts are low-frequency and distributed across many accounts. This makes them less likely to trigger alarms or rate-limiting systems.
How to Detect and Prevent Password Spraying
Stopping password spraying requires more than just account lockout policies. A layered security approach combining monitoring, policy enforcement, and user education is essential.
1. Strong Password Policies
Encourage or enforce strong, unique passwords that are harder to guess. Avoid allowing commonly used passwords, and consider implementing password blacklists.
2. Multi-Factor Authentication (MFA)
MFA adds a critical layer of security. Even if a password is compromised, attackers are blocked without the second factor (e.g., an authenticator app, SMS code, or hardware token).
3. Monitor Login Behavior
Use tools that analyze login patterns across accounts. Flags to watch for include:
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Multiple login attempts from a single IP across many usernames.
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Failed logins using the same password on different accounts.
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Unusual geographic access patterns.
4. Conduct Regular Security Audits
Audit authentication logs and review account security settings regularly. Look for patterns that automated tools might miss and identify weak spots in your defenses.
Additional Security Best Practices
Enhance Login Detection Rules
Set up detection systems that flag suspicious behavior, such as login attempts on multiple accounts from a single host or IP within a short timeframe.
User Training and Awareness
Educate your users about the importance of strong passwords, the dangers of password reuse, and how to spot phishing attempts that can lead to attacks like credential harvesting.
Establish an Incident Response Plan
Have a clear process in place for responding to authentication-related threats. This includes alerting affected users, forcing password resets, and conducting a root cause analysis.
Taking Action Against Password Spraying
Password spraying remains one of the most effective techniques used by cybercriminals and state-sponsored actors to breach systems. Because it exploits weak passwords and flies under the radar, it poses a serious risk to organizations of all sizes.
Protecting against these attacks starts with a strong foundation: enforce strong password hygiene, deploy MFA everywhere possible, and invest in intelligent monitoring tools. With the right safeguards in place, you can dramatically reduce your exposure to this increasingly common threat.
Need help securing your organization?
Contact us for a security consultation and learn how to implement effective defenses against password spraying and other advanced cyber threats.
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