Entra ID Device Code Auth with Broker Client

Identifies device code authentication with an Azure broker client for Entra ID. Adversaries abuse Primary Refresh Tokens (PRTs) to bypass multi-factor authentication (MFA) and gain unauthorized access to Azure resources. PRTs are used in Conditional Access policies to enforce device-based controls. Compromising PRTs allows attackers to bypass these policies and gain unauthorized access. This rule detects successful sign-ins using device code authentication with the Entra ID broker client application ID (29d9ed98-a469-4536-ade2-f981bc1d605e).

Rule type: query

Rule indices:

filebeat-*
logs-azure.signinlogs-*
logs-azure.activitylogs-*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Domain: Cloud
Data Source: Azure
Data Source: Microsoft Entra ID
Use Case: Identity and Access Audit
Tactic: Credential Access

Version: 1

Rule authors:

Elastic

Rule license: Elastic License v2

Setup

edit

This rule optionally requires Azure Sign-In logs from the Azure integration. Ensure that the Azure integration is correctly set up and that the required data is being collected.

Rule query

edit

 event.dataset:(azure.activitylogs or azure.signinlogs)
    and azure.signinlogs.properties.authentication_protocol:deviceCode
    and azure.signinlogs.properties.conditional_access_audiences.application_id:29d9ed98-a469-4536-ade2-f981bc1d605e
    and event.outcome:success or (
        azure.activitylogs.properties.appId:29d9ed98-a469-4536-ade2-f981bc1d605e
        and azure.activitylogs.properties.authentication_protocol:deviceCode)

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
Technique:
- Name: Steal Application Access Token
- ID: T1528
- Reference URL: https://attack.mitre.org/techniques/T1528/

« Endpoint Security Enumerating Domain Trusts via DSQUERY.EXE »