splunk_escuAnomaly

Cisco Isovalent - Cron Job Creation

The following analytic detects the creation of a cron job within the Cisco Isovalent environment. It identifies this activity by monitoring process execution logs for cron job creation events. This behavior is significant for a SOC as it could allow an attacker to execute malicious tasks repeatedly and automatically, posing a threat to the Kubernetes infrastructure. If confirmed malicious, this activity could lead to persistent attacks, service disruptions, or unauthorized access to sensitive information.

Detection Query

`cisco_isovalent_process_exec` process_name IN ("crond","cron","crontab")
| search pod_name!=""
| stats count
        min(_time) as firstTime
        max(_time) as lastTime
        values(process) as process
    by cluster_name pod_name parent_process_name process_name process_exec process_id node_name
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `cisco_isovalent___cron_job_creation_filter`

Author

Bhavin Patel, Splunk

Data Sources

Cisco Isovalent Process Exec

References

Raw Content

name: Cisco Isovalent - Cron Job Creation
id: 94531a31-a041-4777-909f-cd92ed3b71ad
version: 5
creation_date: '2026-01-05'
modification_date: '2026-05-13'
author: Bhavin Patel, Splunk
status: production
type: Anomaly
description: The following analytic detects the creation of a cron job within the Cisco Isovalent environment. It identifies this activity by monitoring process execution logs for cron job creation events. This behavior is significant for a SOC as it could allow an attacker to execute malicious tasks repeatedly and automatically, posing a threat to the Kubernetes infrastructure. If confirmed malicious, this activity could lead to persistent attacks, service disruptions, or unauthorized access to sensitive information.
data_source:
    - Cisco Isovalent Process Exec
search: |
    `cisco_isovalent_process_exec` process_name IN ("crond","cron","crontab")
    | search pod_name!=""
    | stats count
            min(_time) as firstTime
            max(_time) as lastTime
            values(process) as process
        by cluster_name pod_name parent_process_name process_name process_exec process_id node_name
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `cisco_isovalent___cron_job_creation_filter`
how_to_implement: The detection is based on process execution data generated by Cisco Isovalent Runtime Security. Ensure that Isovalent Runtime Security is deployed and configured in your Kubernetes environment to emit process_exec events. Configure the Cisco Security Cloud TA to collect these logs via HTTP Event Collector (HEC) and normalize them into the Splunk Common Information Model. This integration ensures that all relevant pod, container, and process activity is captured for monitoring and detection of suspicious behavior.
known_false_positives: This activity may be triggered by legitimate administrative scripts, container images, or third-party operators that use cron for scheduled tasks, so please investigate the alert in context to rule out benign operations.
references:
    - https://attack.mitre.org/techniques/T1053/003/
    - https://medium.com/@bag0zathev2/cronjobs-for-hackers-bugbounty-article-7d51588d0fd5
    - https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/
drilldown_searches:
    - name: View the detection results for - "$pod_name$"
      search: '%original_detection_search% | search pod_name = "$pod_name$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$pod_name$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$pod_name$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: pod_name
          type: system
          score: 20
          message: cron job creation detected in pod [$pod_name$] in the cluster [$cluster_name$]
threat_objects:
    - field: process_name
      type: process_name
analytic_story:
    - Cisco Isovalent Suspicious Activity
asset_type: Kubernetes
mitre_attack_id:
    - T1053.003
    - T1053.007
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/cisco_isovalent/cisco_isovalent.log
          source: not_applicable
          sourcetype: cisco:isovalent:processExec
      test_type: unit