Azure Risk Detection: Attempted Primary Refresh Token (PRT) Access

Identifies Azure risk events indicating an attempted PRT access that can enable lateral movement or credential theft.

FreeReviewedSigma · High · v5

Product: azure
Service: riskdetection
Author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo' (SigmaHQ), DRL 1.1
Published: 2023-09-07
Updated: 2026-07-31

ATT&CK techniques

Cred Access

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
- T1528Steal Application Access Token
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags risk events where there is an attempted access to the Primary Refresh Token (PRT) resource. Attempted PRT access is significant because it may enable lateral movement within an organization or facilitate credential theft. The detection relies on Azure risk telemetry with riskEventType set to attemptedPrtAccess.

Reporting behind it

Related detections9 linkedT1528 — drag to rearrange

Malicious OAuth Application Granted Full Mailbox and EWS Permissions (via m365)

Suspicious GAM OAuth Token Enumeration via Process Creation

Suspicious Entra ID Device Code Flow Authentication

Suspicious Delegated Permission Grant to Entra Agent Access Scope via Azure Audit Logs

Suspicious OAuth Application Registration with Localhost Reply URL via Azure AD

Malicious PRT Token Forging via AADInternals (via ps_script)

Possible VMware Workspace ONE SSRF via instanceHealth hostName At-Injection (via webserver)

Suspicious Entra Device Code Authentication with Office Client and Automated User Agent

Suspicious Access to Kubernetes Service Account Token via Curl or Wget (via process_creation)

Azure Risk Detection: Attempted Primary Refresh Token (PRT) Access

Pivot detection · T1528 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

azure-riskdetection-attempted-primary-refresh-token-prt-access-a84fc3b1

title: "Azure Risk Detection: Attempted Primary Refresh Token (PRT) Access"
id: 6d490b24-cf60-4404-87fc-f8143d3fd3e5
status: test
description: This rule flags risk events where there is an attempted access to the Primary Refresh Token (PRT) resource. Attempted PRT access is significant because it may enable lateral movement within an organization or facilitate credential theft. The detection relies on Azure risk telemetry with riskEventType set to attemptedPrtAccess.
references:
  - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#possible-attempt-to-access-primary-refresh-token-prt
  - https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/identity_protection/azure_identity_protection_prt_access.yml
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo', Huntrule Team
date: 2023-09-07
tags:
  - attack.t1528
  - attack.credential-access
logsource:
  product: azure
  service: riskdetection
detection:
  selection:
    riskEventType: attemptedPrtAccess
  condition: selection
falsepositives:
  - This detection is low-volume and is seen infrequently in most organizations. When this detection appears it's high risk, and users should be remediated.
level: high
license: DRL-1.1
related:
  - id: a84fc3b1-c9ce-4125-8e74-bdcdb24021f1
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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