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Kubernetes CronJob/Job Modification

Detects when a Kubernetes CronJob or Job is created or modified. A Kubernetes Job creates one or more pods to accomplish a specific task, and a CronJob creates Jobs on a recurring schedule. An adversary can take advantage of this Kubernetes object to schedule Jobs to run containers that execute malicious code within a cluster, allowing them to achieve persistence.

Detection Query

selection:
  objectRef.apiGroup: batch
  objectRef.resource:
    - cronjobs
    - jobs
  verb:
    - create
    - delete
    - patch
    - replace
    - update
condition: selection

Author

kelnage

Created

2024-07-11

Data Sources

kubernetesaudit

Platforms

kubernetes

References

Tags

attack.persistenceattack.privilege-escalationattack.execution

Raw Content

title: Kubernetes CronJob/Job Modification
id: 0c9b3bda-41a6-4442-9345-356ae86343dc
related:
    - id: cd3a808c-c7b7-4c50-a2f3-f4cfcd436435
      type: similar
status: test
description: |
    Detects when a Kubernetes CronJob or Job is created or modified.
    A Kubernetes Job creates one or more pods to accomplish a specific task, and a CronJob creates Jobs on a recurring schedule.
    An adversary can take advantage of this Kubernetes object to schedule Jobs to run containers that execute malicious code within a cluster, allowing them to achieve persistence.
references:
    - https://kubernetes.io/docs/reference/config-api/apiserver-audit.v1/
    - https://www.redhat.com/en/blog/protecting-kubernetes-against-mitre-attck-persistence#technique-33-kubernetes-cronjob
author: kelnage
date: 2024-07-11
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
logsource:
    product: kubernetes
    service: audit
detection:
    selection:
        objectRef.apiGroup: 'batch'
        objectRef.resource:
            - 'cronjobs'
            - 'jobs'
        verb:
            - 'create'
            - 'delete'
            - 'patch'
            - 'replace'
            - 'update'
    condition: selection
falsepositives:
    - Modifying a Kubernetes Job or CronJob may need to be done by a system administrator.
    - Automated processes may need to take these actions and may need to be filtered.
level: medium