Multifactor Authentication Interrupted — Sigma Rule

Rule metadata and linked tags

Author: AlertIQ. Source status: test; severity: medium. Source dates: 2021-10-10 / 2022-12-18.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 99d485c6f264989165b939b54e1b67e92f23d3951eab433e901cf34d3b4e8b91

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: Multifactor Authentication Interrupted
id: 5496ff55-42ec-4369-81cb-00f417029e25
status: test
description: Identifies user login with multifactor authentication failures, which might be an indication an attacker has the password for the account but can't pass the MFA challenge.
references:
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-privileged-accounts
author: AlertIQ
date: 2021-10-10
modified: 2022-12-18
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.initial-access
    - attack.credential-access
    - attack.stealth
    - attack.t1078.004
    - attack.t1110
    - attack.t1621
logsource:
    product: azure
    service: signinlogs
detection:
    selection_50074:
        ResultType: 50074
        ResultDescription|contains: 'Strong Auth required'
    selection_500121:
        ResultType: 500121
        ResultDescription|contains: 'Authentication failed during strong authentication request'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://learn.microsoft.com/en-us/entra/architecture/security-operations-privileged-accounts