What is Password Spraying?

Password spraying is a type of cyberattack where an attacker attempts to gain unauthorized access to multiple user accounts by using a few common passwords across many accounts. Read on for an overview of password spray attacks, how they work, how to detect them, and how to defend against them.

Example of a password spray attack

How Does an Attacker Carry Out a Password Spray Attack?

An attacker carries out a password spray attack by selecting a small set of common passwords, such as "123456" or "passw0rd."

They use automated tools to systematically test these passwords across a vast number of user accounts.

Moreover, the attacker often avoids triggering account lockouts by trying only a few passwords against each account. This password cracking technique also minimizes the risk of the threat actor's detection and lockouts on a single account due to the time between attempts.

How Common is Password Spraying?

Microsoft estimates that password spray attacks are responsible for more than a third of all account compromises in organizations.

Password spraying is a prevalent attack technique because it exploits the human tendency to use weak passwords and reuse them across multiple accounts. Many organizations fall victim to this type of attack, making it a considerable cybersecurity concern.

What Are Some Examples of Password Spraying?

Using a list of common weak passwords, such as 123456 or passw0rd, an attacker can potentially access hundreds of accounts in one attack.

Examples of some common passwords targeted in a password spraying attack are:

How Midnight Blizzard Breached Microsoft via a Spray Attack

In November 2023, the nation-state threat actor group, Midnight Blizzard (also known as Nobelium), targeted Microsoft with an unsophisticated spray attack. By using a massive number of legitimate residential IP addresses to help evade detection in launching their password sprays attacks, Midnight Blizzard succeeded in breaching a Microsoft legacy test tenant account that had admin privileges and lacked MFA. This enabled the threat actors to move laterally and identify and compromise a legacy test OAuth application with privileged access, giving the attackers persistence in the system. In the two months before Microsoft discovered the breach, the threat actors exfiltrated emails, attachments, and (potentially) data from key Microsoft executives and employees.

How Effective Are Password Spray Attacks?

The success of a password spray attack depends on the number of weak or reused passwords within the targeted organization.

With poor password hygiene by any one user or on any single account, the threat actor will likely succeed in infiltrating the resource. If even a small percentage of users have vulnerable passwords, the attacker can potentially gain unauthorized access to multiple accounts, especially if MFA is not enabled. If any of the compromised accounts are privileged, the attacker may then be able to fast-track lateral movement throughout systems and networks.

What Are the Effects of Password Spraying?

The effects of successful password spraying can be devastating for organizations:

What Is the Difference Between Brute Forcing and Password Spraying?

Brute forcing involves systematically trying all possible combinations of characters to guess a specific user's password. In contrast, password spraying tries a few commonly used passwords against multiple user accounts, aiming to exploit weak passwords across the organization.

Password Spraying Versus Credential Stuffing

Password spraying targets multiple accounts within an organization with a few common passwords. In contrast, credential stuffing involves using a large set of username-password pairs obtained from previous data breaches to gain unauthorized access to various online services.

How Do You Prevent or Mitigate Password Spraying Attacks?

Defending against password spraying attacks requires a proactive, multi-layered cybersecurity approach. Here are some essential strategies to protect your organization:

Use Password Vaults

Each credential across the enterprise should implement password management best practices. This means the password should be unique (not reused for any other application or system—and especially not across personal and work-related systems), it should be complex, and it should not be shared with other users, to name a few best practices. To achieve these practices at scale entails the employment of automated password managers.

Privileged Password Management solutions should be used to secure privileged passwords, accounts, credentials, secrets, and sessions for people and machines. These enterprise solutions are part of privileged access management (PAM) platforms, and essential for enabling a zero trust security posture.

Enterprise password management solutions can also automate workflows to reduce exposure. This includes automatic password rotation if it's determined the credential was or is at risk of compromise.

Implement Multi-Factor Authentication (MFA)

Implement MFA to add an extra layer of protection, requiring users to provide additional verification besides their passwords.

Monitor and Audit User Behavior and Credential Usage

Continuously monitor and detect unusual login attempts and account activities to identify potential password spraying attacks. Regularly review and audit user account access and permissions to ensure only authorized personnel (employees, vendors, etc.) have appropriate privileges.

Account Lockout Mechanisms

Enable account lockouts after a certain number of unsuccessful login attempts to thwart brute force and password spray attacks.

Authentication-Based Attacks & Defense - Next Steps

Password spraying remains a prevalent threat in the cybersecurity landscape, underscoring the need for a robust and holistic cybersecurity protocol, including password vaults, multi-factor authentication, monitoring and auditing of user behavior, and account lockout mechanisms, to name a few. Additionally, setting stringent standards for using and frequently rotating unique passwords is paramount for protecting sensitive information.

To get detection and protection against password sprays and other identity-based attacks, contact BeyondTrust today.

For more learning on protecting against account hijacking and identity-based attacks, check out the resources below.

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