Google Cloud Kubernetes CronJob

Status: test
Severity: medium
Log source: product gcp, service gcp.audit
Author: Austin Songer @austinsonger
Source: github.com/SigmaHQ/sigma

Identifies when a Google Cloud Kubernetes CronJob runs in Azure Cloud. Kubernetes Job is a controller that creates one or more pods and ensures that a specified number of them successfully terminate. Kubernetes Job can be used to run containers that perform finite tasks for batch jobs. Kubernetes CronJob is used to schedule Jobs. An Adversary may use Kubernetes CronJob for scheduling execution of malicious code that would run as a container in the cluster.

Known false positives

Google Cloud Kubernetes CronJob/Job may be done by a system administrator.
If known behavior is causing false positives, it can be exempted from the rule.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	No specific technique
Persistence	No specific technique
Privilege Escalation	No specific technique

Rule body

title: Google Cloud Kubernetes CronJob
id: cd3a808c-c7b7-4c50-a2f3-f4cfcd436435
status: test
description: |
    Identifies when a Google Cloud Kubernetes CronJob runs in Azure Cloud. Kubernetes Job is a controller that creates one or more pods and ensures that a specified number of them successfully terminate.
    Kubernetes Job can be used to run containers that perform finite tasks for batch jobs. Kubernetes CronJob is used to schedule Jobs.
    An Adversary may use Kubernetes CronJob for scheduling execution of malicious code that would run as a container in the cluster.
references:
    - https://cloud.google.com/kubernetes-engine/docs
    - https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/
    - https://kubernetes.io/docs/concepts/workloads/controllers/job/
author: Austin Songer @austinsonger
date: 2021-11-22
modified: 2022-12-25
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
logsource:
    product: gcp
    service: gcp.audit
detection:
    selection:
        gcp.audit.method_name:
            - io.k8s.api.batch.v*.Job
            - io.k8s.api.batch.v*.CronJob
    condition: selection
falsepositives:
    - Google Cloud Kubernetes CronJob/Job may be done by a system administrator.
    - If known behavior is causing false positives, it can be exempted from the rule.
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    gcp.audit.method_name:
        - io.k8s.api.batch.v*.Job
        - io.k8s.api.batch.v*.CronJob

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`gcp.audit.method_name`	wildcard	`io.k8s.api.batch.v.CronJob` `io.k8s.api.batch.v.Job`	`field:"gcp::method_name" kind:wildcard`