Password spraying is a credential attack that works by attempting to authenticate, with one or more commonly used passwords, across a large number of usernames rather than repeatedly attacking a single account. The goal is to find weak passwords without triggering lockout thresholds or create brute-force alerts to monitoring systems or a SoC.
This type of attack differs from traditional brute-force attacks (which tests many password guesses against one account). In a password spraying attack the attacker might attempt values such as “Spring2026!” or “CompanyName123” once across hundreds of users and then wait and repeat with a different password after a brief interval. Because each account sees only a small number of failed attempts the activity can blend into normal authentication background noise.
The technique is particularly effective against externally exposed services such as Microsoft 365, VPN portals, webmail, and single sign-on interfaces. It also works well on internal networks where there is a weak password policy or where users have predictable patterns for seasonal password changes. Even if most users choose strong passwords, one weak account may be enough for an attacker to gain initial entry, access email, or begin lateral movement .
This technique is commonly exercised during internal penetration testing and is closely related to brute force and credential stuffing attack methods. Strong password policies, MFA, and monitoring for authentication failure patterns can materially reduce the risk.