splunk_escuAnomaly

Cisco Isovalent - Curl Execution With Insecure Flags

The following analytic detects the execution of curl commands with insecure flags within the Cisco Isovalent environment. It identifies this activity by monitoring process execution logs for curl commands that use the -k or --insecure flags. This behavior is significant for a SOC as it could allow an attacker to bypass SSL/TLS verification, potentially exposing the Kubernetes infrastructure to man-in-the-middle attacks. If confirmed malicious, this activity could lead to data interception, service disruptions, or unauthorized access to sensitive information.

MITRE ATT&CK

T1105

Detection Query

`cisco_isovalent_process_exec`  process_name="curl"
| regex process="(?i)(?<!\w)-(?:[a-z]*k[a-z]*|-(insecure|proxy-insecure|doh-insecure))"
| 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___curl_execution_with_insecure_flags_filter`

Author

Bhavin Patel, Splunk

Created

2026-03-10

Data Sources

Cisco Isovalent Process Exec

References

Tags

Cisco Isovalent Suspicious Activity

Raw Content

name: Cisco Isovalent - Curl Execution With Insecure Flags
id: c16c4899-d3f7-461b-92c2-cc0ef5758855
version: 3
date: '2026-03-10'
author: Bhavin Patel, Splunk
type: Anomaly
data_source:
    - Cisco Isovalent Process Exec
status: production
description: The following analytic detects the execution of curl commands with insecure flags within the Cisco Isovalent environment. It identifies this activity by monitoring process execution logs for curl commands that use the -k or --insecure flags. This behavior is significant for a SOC as it could allow an attacker to bypass SSL/TLS verification, potentially exposing the Kubernetes infrastructure to man-in-the-middle attacks. If confirmed malicious, this activity could lead to data interception, service disruptions, or unauthorized access to sensitive  information.
search: |
    `cisco_isovalent_process_exec`  process_name="curl"
    | regex process="(?i)(?<!\w)-(?:[a-z]*k[a-z]*|-(insecure|proxy-insecure|doh-insecure))"
    | 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___curl_execution_with_insecure_flags_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://rawcode7.medium.com/understanding-the-kubernetes-attack-surface-9a48ebcb6bc4
    - https://www.tutorialworks.com/kubernetes-curl/
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 ("$pod_name$") starthoursago=168  | 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: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: A curl execution with insecure flags has been detected on pod_name [$pod_name$] in the cluster [$cluster_name$]
    risk_objects:
        - field: pod_name
          type: system
          score: 20
    threat_objects:
        - field: process_name
          type: process_name
tags:
    analytic_story:
        - Cisco Isovalent Suspicious Activity
    asset_type: Endpoint
    mitre_attack_id:
        - T1105
    atomic_guid:
        - 7e2ad0db-1efa-4af2-a77c-bc6e87d7b3f3
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
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