Password spraying is one of today’s most dangerous and underestimated cyberattack methods. It’s subtle, hard to detect, and relies on something far too common—weak or reused passwords.
Unlike traditional brute-force attacks that target one account with many password attempts, password spraying flips the script. Instead, attackers use a few common passwords and test them across hundreds or thousands of accounts. The method is slow, deliberate, and designed to fly under the radar.
In this post, we’ll break down how password spraying works, how it compares to other types of attacks, and—most importantly—how to defend your business against it.
What Is Password Spraying?
Password spraying is a type of brute-force attack in which hackers try one password against many usernames before rotating to the next. This method is designed to bypass lockout policies that limit the number of failed login attempts for individual accounts.
Here’s how it usually plays out:
An attacker obtains a list of usernames (commonly through data breaches, LinkedIn, or company email structures).
They select a few common passwords like Password123 or Welcome2024.
Using automated tools, they test each password across all accounts—often slowly enough to avoid triggering alerts.
It’s especially effective in environments where users reuse passwords or follow predictable patterns (e.g., companyname2024).
The stealthy nature of password spraying makes it a preferred tactic for both cybercriminals and state-sponsored attackers, especially when targeting enterprises or government agencies.
How Password Spraying Differs from Other Attacks
While password spraying is technically a form of brute-force attack, it’s not as loud or fast as traditional methods. Let’s compare:
| Attack Type | Target | Approach | Detection Risk |
|---|---|---|---|
| Brute-force | One account | Many passwords | High – rapid failures |
| Credential stuffing | Multiple accounts | Known password+username combos | Medium |
| Password spraying | Multiple accounts | Few common passwords | Low – spread out attempts |
Unlike credential stuffing, which uses leaked credentials, password spraying doesn’t require breached data—just a list of usernames and a few guesses.
Because login attempts are spaced out and randomized, these attacks often go undetected until it’s too late.
Why Password Spraying Works So Well
Attackers know that users:
Reuse passwords across accounts
Use weak passwords or predictable formats
Rarely update passwords
Don’t always enable MFA
This gives hackers an edge, especially in large organizations with hundreds of users. Even if just one account is compromised, it could give an attacker access to email, file storage, or worse—administrator privileges.
Unfortunately, many businesses don’t realize they’ve been breached until long after data has been accessed or stolen.
How to Detect a Password Spraying Attack
You can’t stop what you can’t see. Here are red flags that may indicate password spraying:
Multiple failed login attempts across many accounts from a single IP address
Logins at odd hours or from unusual geolocations
Lockout patterns clustered across different users
Spike in Help Desk requests for locked accounts or MFA issues
Modern security tools such as SIEM platforms or identity threat detection tools (like Microsoft Defender or SentinelOne) can help detect these behaviors—but only if they’re configured properly.
How to Defend Your Organization Against Password Spraying
Preventing password spraying isn’t about one single tool—it’s a layered approach. Here’s what every business should implement:
1. Enforce Strong Password Policies
Avoid weak or commonly used passwords. Require long, complex passwords with a mix of characters. Consider banning known bad passwords using tools like Have I Been Pwned’s password list.
2. Require Multi-Factor Authentication (MFA)
Even if a password is compromised, MFA blocks access. It’s one of the most effective defenses against password spraying and should be required for every user.
3. Monitor Authentication Logs
Use log analytics to monitor for patterns like:
Single IP, multiple accounts
Failed login attempts at scale
Logins from foreign IPs
This is where tools like ParJenn’s Managed Detection and Response can help automate alerts and responses.
4. Limit Legacy Authentication
Disable older authentication methods (like IMAP, POP, and SMTP Basic Auth) that don’t support MFA. These are frequently targeted in password spraying campaigns.
5. Conduct Regular Security Awareness Training
Educate your users about password security, the risks of reuse, and why MFA matters. The more your employees understand, the less vulnerable they are.
Real-World Example: Password Spraying in Action
In 2021, Microsoft reported that state-sponsored groups were using password spraying attacks to target organizations across the U.S. and Europe. These attackers used commonly available tools like Exchange Online and legacy protocols to evade detection and gain access to sensitive systems.
This wasn’t a case of advanced malware or zero-day exploits—it was weak passwords and a lack of MFA.
Final Thoughts: Stay One Step Ahead
Password spraying is successful because it exploits the predictable behavior of users. But you don’t have to make it easy for attackers.
By using strong passwords, enabling MFA, monitoring logins, and investing in security training, you can dramatically reduce your risk. Don’t wait until you’re the next breach headline.
Want help implementing these security best practices? Contact us today for a personalized cybersecurity audit.
