M365 Identity OAuth Illicit Consent Grant by Rare Client and User

Last updated 23 days ago on 2025-12-10

Created 9 months ago on 2025-03-24

About

Identifies an Microsoft 365 illicit consent grant request on-behalf-of a registered Entra ID application. Adversaries may create and register an application in Microsoft Entra ID for the purpose of requesting user consent to access resources in Microsoft 365. This is accomplished by tricking a user into granting consent to the application, typically via a pre-made phishing URL. This establishes an OAuth grant that allows the malicious client applocation to access resources in Microsoft 365 on-behalf-of the user.

Tags

Domain: CloudData Source: Microsoft 365Data Source: Microsoft 365 Audit LogsUse Case: Identity and Access AuditTactic: Initial AccessTactic: Credential AccessLanguage: kuery

Severity

medium

Risk Score

MITRE ATT&CK™

Initial Access (TA0001)(external, opens in a new tab or window)

↳ Phishing (T1566)(external, opens in a new tab or window)

Credential Access (TA0006)(external, opens in a new tab or window)

↳ Steal Application Access Token (T1528)(external, opens in a new tab or window)

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: New Terms Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-o365.audit-*
Related Integrations: o365(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗event.dataset: "o365.audit"
  and o365.audit.Actor.Type: 5
  and event.action: "Consent to application."
  and event.outcome: "success"
  and o365.audit.Target.Type: (0 or 2 or 3 or 9 or 10)

Install detection rules in Elastic Security

Detect M365 Identity OAuth Illicit Consent Grant by Rare Client and User in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).