Azure Kubernetes Network Policy Change — Sigma Rule

Rule metadata and linked tags

Author: Austin Songer @austinsonger. Source status: test; severity: medium. Source dates: 2021-08-07 / 2022-08-23.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 364590409a4fd2382dbfb332219a412dc135d3991f5fbd500632f9830a787d2e

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: Azure Kubernetes Network Policy Change
id: 08d6ac24-c927-4469-b3b7-2e422d6e3c43
status: test
description: Identifies when a Azure Kubernetes network policy is modified or deleted.
references:
    - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations#microsoftkubernetes
    - https://www.microsoft.com/security/blog/2021/03/23/secure-containerized-environments-with-updated-threat-matrix-for-kubernetes/
    - https://www.microsoft.com/security/blog/2020/04/02/attack-matrix-kubernetes/
    - https://medium.com/mitre-engenuity/att-ck-for-containers-now-available-4c2359654bf1
author: Austin Songer @austinsonger
date: 2021-08-07
modified: 2022-08-23
tags:
    - attack.impact
    - attack.credential-access
    - attack.t1485
    - attack.t1496
    - attack.t1489
logsource:
    product: azure
    service: activitylogs
detection:
    selection:
        operationName:
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/NETWORKING.K8S.IO/NETWORKPOLICIES/WRITE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/NETWORKING.K8S.IO/NETWORKPOLICIES/DELETE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/EXTENSIONS/NETWORKPOLICIES/WRITE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/EXTENSIONS/NETWORKPOLICIES/DELETE
    condition: selection
falsepositives:
    - Network Policy being modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - Network Policy being modified and deleted from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

Original YAML and metadata in JSON

False positives

• Network Policy being modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
• Network Policy being modified and deleted from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

Source references

• https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations#microsoftkubernetes
• https://www.microsoft.com/security/blog/2021/03/23/secure-containerized-environments-with-updated-threat-matrix-for-kubernetes/
• https://www.microsoft.com/security/blog/2020/04/02/attack-matrix-kubernetes/
• https://medium.com/mitre-engenuity/att-ck-for-containers-now-available-4c2359654bf1