Azure Kubernetes RoleBinding/ClusterRoleBinding Modified and Deleted — 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: 31a9d404a54dde367db6165a1473bf76b7054c597d505ec6576c056cec889bf5

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 RoleBinding/ClusterRoleBinding Modified and Deleted
id: 25cb259b-bbdc-4b87-98b7-90d7c72f8743
status: test
description: Detects the creation or patching of potential malicious RoleBinding/ClusterRoleBinding.
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/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/WRITE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/DELETE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/WRITE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/DELETE
    condition: selection
falsepositives:
    - RoleBinding/ClusterRoleBinding 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.
    - RoleBinding/ClusterRoleBinding modification 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

• RoleBinding/ClusterRoleBinding 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.
• RoleBinding/ClusterRoleBinding modification 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