Primary Refresh Token Access Attempt — Sigma Rule

Rule metadata and linked tags

Author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'. Source status: test; severity: high. Source dates: 2023-09-07 / not supplied.

{
  "product": "azure",
  "service": "riskdetection"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: e58f7475bc395695bf7f693c45e997465d00075dd84c61aa2a971cfb34ed4274

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Primary Refresh Token Access Attempt
id: a84fc3b1-c9ce-4125-8e74-bdcdb24021f1
status: test
description: Indicates access attempt to the PRT resource which can be used to move laterally into an organization or perform credential theft
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
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
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

Original YAML and metadata in JSON

False positives

• 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.

Source 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