What Is Password Spraying?

Password spraying is a login attack that tries a small number of common passwords across many user accounts. Instead of guessing many passwords for one account, the attacker spreads a few likely passwords across a large set of usernames to avoid lockouts and identify weak credentials.

This makes password spraying different from a classic brute-force attack. It is quieter, often more effective against exposed login portals, and commonly used against cloud email, VPN, SSO, and other identity systems. For related background, see what is credential stuffing and what is mfa.

How password spraying works

The attacker gathers usernames

The first step is getting a list of valid or likely account names. Attackers may collect usernames from:

• Company websites
• LinkedIn profiles
• Public email formats
• Data from previous breaches
• Exposed directories or login prompts
• Employee naming conventions

The attacker does not need every username to be valid. They just need enough real accounts to make a few successful guesses likely.

The attacker chooses a small set of common passwords

Instead of trying hundreds of passwords, the attacker selects a few likely ones. These may include:

• Seasonal passwords
• Company-name variations
• Default or temporary passwords
• Weak patterns such as simple numbers or common words

The point is efficiency. If even a small portion of users have weak passwords, the attacker may get valid logins with very few attempts.

The attacker spaces attempts to avoid lockouts

This is what makes password spraying distinct from traditional brute force. Many environments lock an account after too many failed attempts in a short period. To stay below that threshold, the attacker may:

• Try one password across many accounts
• Wait for the lockout window to reset
• Try a second password later
• Rotate through multiple IP addresses or regions

Because no single account receives many rapid failures, the activity can be harder to spot without identity-aware monitoring.

The attacker targets internet-facing login systems

Password spraying is commonly aimed at services that are reachable from the internet, such as:

• Cloud email portals
• VPN gateways
• Single sign-on platforms
• Webmail
• Remote desktop gateways
• SaaS login pages
• Federated identity services

These systems are attractive because a single successful login can provide broad access.

The attacker uses successful credentials for follow-on activity

Once the attacker finds working credentials, they may:

• Access email and internal conversations
• Pivot into cloud apps
• Reset passwords or abuse self-service workflows
• Harvest more contacts and credentials
• Launch business email compromise
• Attempt MFA fatigue or session abuse
• Establish longer-term identity persistence

Password spraying is often an entry method, not the final objective.

Why password spraying works

Password spraying remains effective because many organizations still have gaps such as:

• Weak password choices
• Incomplete MFA coverage
• Stale or forgotten accounts
• Internet-exposed authentication portals
• Limited login monitoring
• Legacy protocols that bypass modern controls

Attackers do not always need malware or a software exploit if the login page itself is the easiest way in.

When you are likely to encounter password spraying

You are most likely to encounter password spraying in environments with internet-facing authentication and large numbers of user accounts.

Common scenarios include:

• Microsoft 365 or Google Workspace sign-in activity
• VPN and remote access portals
• Single sign-on logs
• Hybrid identity environments
• Organizations with many stale, guest, or service accounts
• SMBs with limited identity monitoring

From a defender’s perspective, password spraying often appears as:

• Many failed sign-ins across multiple users
• Repeated attempts using the same password pattern
• Authentication from suspicious IP ranges
• Activity outside normal business hours
• Login attempts against dormant or rarely used accounts

Password spraying vs related attacks

Password spraying vs brute force

A brute-force attack tries many passwords against one account or one secret until it works. Password spraying flips that model by trying a few passwords across many accounts.

Password spraying vs credential stuffing

Credential stuffing uses username-password pairs stolen from previous breaches and tests them on other services. Password spraying usually uses guessed common passwords rather than known stolen pairs.

Password spraying vs phishing

Phishing tries to trick users into handing over credentials or approving access. Password spraying does not need user interaction. It directly tests passwords against authentication systems.

How to reduce password spraying risk

Enforce strong, unique passwords

Weak and predictable passwords are what make password spraying viable. Organizations should require longer, unique passwords and eliminate common or default choices.

For individuals and small teams, a password manager like Try 1Password → can make it much easier to use strong, unique passwords across accounts.

Require MFA broadly

MFA significantly reduces the value of a successfully sprayed password. It is especially important for:

• Email accounts
• Admin accounts
• VPN access
• SSO platforms
• Remote access systems

Coverage matters. Gaps in MFA enforcement, exception groups, and legacy access methods can still leave openings.

Monitor authentication patterns

Look for:

• One password pattern tried across many accounts
• Spikes in failed sign-ins
• Repeated login attempts from unusual geographies
• Attempts against dormant accounts
• Distributed failures from rotating IP addresses

Good detection at the identity layer is often the fastest way to catch spraying activity.

Remove stale and risky accounts

Dormant accounts, test users, and legacy service accounts expand the attack surface. Review and disable accounts that are no longer needed.

Harden exposed login surfaces

Reduce unnecessary internet exposure, limit legacy authentication, and apply conditional access where possible. If remote users rely on public networks, a VPN such as Check NordVPN pricing → or Try Proton VPN → can help protect traffic in transit, though it does not stop password spraying by itself.

For endpoints that may also face malware or credential theft attempts, endpoint protection such as Get Malwarebytes → can be a useful supporting control.

Why MFA still matters even if attackers spray passwords

Even when attackers guess a valid password, MFA can block straightforward account takeover. That said, defenders should not assume MFA solves everything. Attackers may still look for:

• Accounts not enrolled in MFA
• Legacy protocols
• Service accounts
• MFA fatigue opportunities
• Session token theft after login

Password spraying is most dangerous in environments where identity controls are inconsistent.

Final takeaway

Password spraying is a credential attack that tries a small set of common passwords across many accounts to avoid lockouts and find weak credentials. It is quieter than traditional brute force and especially relevant for cloud email, VPN, SSO, and other internet-facing authentication systems.

The best defenses are strong unique passwords, broad MFA enforcement, reduced exposure of login services, and monitoring that can spot repeated failures across many accounts rather than just one.