Activity from Anonymous IP Addresses — Sigma Rule

Rule metadata and linked tags

Author: Austin Songer @austinsonger. Source status: test; severity: medium. Source dates: 2021-08-23 / 2022-10-09.

{
  "service": "threat_management",
  "product": "m365"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 3279465203c56b1ec7e2b972655cc5064e43ebf9f95f769f60385e43283808e2

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: Activity from Anonymous IP Addresses
id: d8b0a4fe-07a8-41be-bd39-b14afa025d95
status: test
description: Detects when a Microsoft Cloud App Security reported when users were active from an IP address that has been identified as an anonymous proxy IP address.
references:
    - https://learn.microsoft.com/en-us/defender-cloud-apps/anomaly-detection-policy
    - https://learn.microsoft.com/en-us/defender-cloud-apps/policy-template-reference
author: Austin Songer @austinsonger
date: 2021-08-23
modified: 2022-10-09
tags:
    - attack.command-and-control
    - attack.t1573
logsource:
    service: threat_management
    product: m365
detection:
    selection:
        eventSource: SecurityComplianceCenter
        eventName: 'Activity from anonymous IP addresses'
        status: success
    condition: selection
falsepositives:
    - User using a VPN or Proxy
level: medium

Original YAML and metadata in JSON

False positives

• User using a VPN or Proxy

Source references

• https://learn.microsoft.com/en-us/defender-cloud-apps/anomaly-detection-policy
• https://learn.microsoft.com/en-us/defender-cloud-apps/policy-template-reference