O365 Excessive Single Sign-On Logon Errors

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Identifies accounts with a high number of single sign-on (SSO) logon errors. Excessive logon errors may indicate an attempt to brute force a password or SSO token.

Rule type: threshold

Rule indices:

  • filebeat-*
  • logs-o365*

Severity: high

Risk score: 73

Runs every: 5 minutes

Searches indices from: now-20m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

Tags:

  • Elastic
  • Cloud
  • Microsoft 365
  • Continuous Monitoring
  • SecOps
  • Identity and Access

Version: 2 (version history)

Added (Elastic Stack release): 7.14.0

Last modified (Elastic Stack release): 7.15.0

Rule authors: Elastic, Austin Songer

Rule license: Elastic License v2

Potential false positives

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Automated processes that attempt to authenticate using expired credentials and unbounded retries may lead to false positives.

Investigation guide

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## Config

The Microsoft 365 Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.

Rule query

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event.dataset:o365.audit and event.provider:AzureActiveDirectory and
event.category:web and
o365.audit.LogonError:"SsoArtifactInvalidOrExpired"

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 2 (7.15.0 release)
  • Formatting only