O365 Excessive Single Sign-On Logon Errors

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

edit

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

Investigation guide

edit

## Config

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

Rule query

edit

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

Threat mapping

edit

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
Technique:
- Name: Brute Force
- ID: T1110
- Reference URL: https://attack.mitre.org/techniques/T1110/

Rule version history

edit

Version 2 (7.15.0 release)

Formatting only

« NullSessionPipe Registry Modification O365 Exchange Suspicious Mailbox Right Delegation »