Detection rules › Sigma

Suspicious SignIns From A Non Registered Device

Status
test
Severity
high
Log source
product azure, service signinlogs
Author
Harjot Singh, '@cyb3rjy0t'
Source
github.com/SigmaHQ/sigma

Detects risky authentication from a non AD registered device without MFA being required.

MITRE ATT&CK coverage

TacticTechniques
Initial Access
Persistence
Privilege Escalation
Stealth

Telemetry coverage

Rule body

title: Suspicious SignIns From A Non Registered Device
id: 572b12d4-9062-11ed-a1eb-0242ac120002
status: test
description: Detects risky authentication from a non AD registered device without MFA being required.
references:
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-devices#non-compliant-device-sign-in
author: Harjot Singh, '@cyb3rjy0t'
date: 2023-01-10
modified: 2025-07-02
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.initial-access
    - attack.stealth
    - attack.t1078
logsource:
    product: azure
    service: signinlogs
detection:
    selection_main:
        Status: 'Success'
        AuthenticationRequirement: 'singleFactorAuthentication'
        RiskState: 'atRisk'
    selection_empty1:
        DeviceDetail.trusttype: ''
    selection_empty2:
        DeviceDetail.trusttype: null
    condition: selection_main and 1 of selection_empty*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection_main and 1 of selection_empty*

Stage 1: selection_main

selection_main:
    Status: 'Success'
    AuthenticationRequirement: 'singleFactorAuthentication'
    RiskState: 'atRisk'

Stage 2: selection_empty1

selection_empty1:
    DeviceDetail.trusttype: ''

Stage 3: selection_empty2

selection_empty2:
    DeviceDetail.trusttype: null

Indicators

These rows show field, operator, and value matches.