Anonymous IP Address — Sigma Rule

Rule metadata and linked tags

Author: Gloria Lee, '@gleeiamglo'. Source status: test; severity: high. Source dates: 2023-08-22 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 78d11161f3c8b148c7e0cc4ad1084ba66ffa72354f3b5cc16fc232e12a0c447b

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: Anonymous IP Address
id: 53acd925-2003-440d-a1f3-71a5253fe237
status: test
description: Indicates sign-ins from an anonymous IP address, for example, using an anonymous browser or VPN.
references:
    - https://learn.microsoft.com/en-us/graph/api/resources/riskdetection?view=graph-rest-1.0
    - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#anonymous-ip-address
author: Gloria Lee, '@gleeiamglo'
date: 2023-08-22
tags:
    - attack.t1528
    - attack.credential-access
logsource:
    product: azure
    service: riskdetection
detection:
    selection:
        riskEventType: 'anonymizedIPAddress'
    condition: selection
falsepositives:
    - We recommend investigating the sessions flagged by this detection in the context of other sign-ins
level: high

Original YAML and metadata in JSON

False positives

• We recommend investigating the sessions flagged by this detection in the context of other sign-ins

Source references

• https://learn.microsoft.com/en-us/graph/api/resources/riskdetection?view=graph-rest-1.0
• https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#anonymous-ip-address