Malicious IP Address Sign-In Failure Rate — 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: 306495f109bc68bf67a05173a2baa1e1e6ac50ce6c2948688c9999c6977a4437

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: Malicious IP Address Sign-In Failure Rate
id: a3f55ebd-0c01-4ed6-adc0-8fb76d8cd3cd
status: test
description: Indicates sign-in from a malicious IP address based on high failure rates.
references:
    - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#malicious-ip-address
    - 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.t1090
    - attack.command-and-control
logsource:
    product: azure
    service: riskdetection
detection:
    selection:
        riskEventType: 'maliciousIPAddress'
    condition: selection
falsepositives:
    - We recommend investigating the sessions flagged by this detection in the context of other sign-ins from the user.
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 from the user.

Source references

• https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#malicious-ip-address
• https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins