Topic starter
02/02/2026 8:33 pm
TL;DR: Password spraying in Active Directory can evade lockout-based detection by spreading weak-password attempts across many accounts, according to Semperis, and delayed or Kerberos pre-authentication variants make the activity look less suspicious. Detection has to shift from simple failure counts to timing patterns, event-type analysis, and stronger password controls.
Editorial analysis by NHI Mgmt Group, based on content published by Semperis: “Password Spraying Detection in Active Directory”.
Key questions
Q: What breaks when password spraying is not detected early in Windows environments?
A: A single successful spray can convert many weak attempts into one valid session, and that session often becomes the foothold for privilege escalation, remote tooling, and lateral movement.
Q: Why do Kerberos pre-authentication failures matter for password spraying detection?
A: They matter because the attack can move away from standard failed logon events and into a different log signal.
A: Security teams should combine authentication event analysis with baseline-aware detection that looks for repeated, distributed login failures across multiple accounts and systems.
Practitioner guidance
- Harden password policy enforcement Use default domain policy or fine-grained password policies to reduce acceptance of weak passwords across Active Directory accounts.
- Expand detection beyond standard failed logons Include Kerberos pre-authentication failures, especially Event ID 4771 with 0x18, in your alerting and hunting logic.
- Correlate timing across multiple accounts Look for distributed failures that occur at irregular intervals across many users, rather than only bursts against a single account.
Bottom line: Password spraying exploits the gap between per-account lockout rules and distributed credential guessing across many identities.
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This topic was modified 2 days ago by NHI Mgmt Group
10/10/2026 6:47 pm
Active Directory password spraying is a detection design problem, not a simple authentication failure problem: the attack works because most monitoring still assumes repeated guesses against one account. That assumption breaks when guesses are spread across many identities and time windows. Practitioners should treat breadth, timing, and event type as first-class detection inputs, not edge cases.
A question worth separating out:
A: Account lockout and detection alone leave a timing gap that attackers can exploit. AI-assisted spraying can pace attempts just under lockout thresholds, rotate infrastructure, and spread activity across accounts. By the time an alert fires, the password has already been tested. That means the control fails at the point of credential validation, where prevention is most effective.
👉 Read our full editorial: Password spraying detection in Active Directory: what teams miss