[New Rule] Kubeconfig File Discovery

[Aegrah]

Summary

The kubeconfig file is a critical component in Kubernetes environments, containing configuration details for accessing and managing Kubernetes clusters. Attackers may attempt to get access to, create or modify kubeconfig files to gain unauthorized initial access to Kubernetes clusters or move laterally within the cluster. This rule detects process discovery executions that involve kubeconfig files, particularly those executed from common shell environments or world-writeable directories.

Telemetry

Last 30d only 9 hits in telemetry. In my testing stack, only TPs related to manual testing and running reconnaissance tools such as dredge.sh and linpeas.sh.

[github-actions]

Rule: New - Guidelines

These guidelines serve as a reminder set of considerations when proposing a new rule.

Documentation and Context

• Detailed description of the rule.
• List any new fields required in ECS/data sources.
• Link related issues or PRs.
• Include references.

Rule Metadata Checks

• creation_date matches the date of creation PR initially merged.
• min_stack_version should support the widest stack versions.
• name and description should be descriptive and not include typos.
• query should be inclusive, not overly exclusive, considering performance for diverse environments. Non ecs fields should be added to non-ecs-schema.json if not available in an integration.
• min_stack_comments and min_stack_version should be included if the rule is only compatible starting from a specific stack version.
• index pattern should be neither too specific nor too vague, ensuring it accurately matches the relevant data stream (e.g., use logs-endpoint.process-* for process data).
• integration should align with the index. If the integration is newly introduced, ensure the manifest, schemas, and new_rule.yaml template are updated.
• setup should include the necessary steps to configure the integration.
• note should include any additional information (e.g. Triage and analysis investigation guides, timeline templates).
• tags should be relevant to the threat and align/added to the EXPECTED_RULE_TAGS in the definitions.py file.
• threat, techniques, and subtechniques should map to ATT&CK always if possible.

New BBR Rules

• building_block_type should be included if the rule is a building block and the rule should be located in the rules_building_block folder.
• bypass_bbr_timing should be included if adding custom lookback timing to the rule.

Testing and Validation

• Provide evidence of testing and detecting the expected threat.
• Check for existence of coverage to prevent duplication.

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Kubeconfig File Discovery (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Kubeconfig File Discovery (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Kubeconfig File Discovery (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta