[New Rule] ICMP Redirect Message from Internal Host

[eric-forte-elastic]

Pull Request

Issue link(s):

Summary - What I changed

Adds a new query network detection rule that identifies ICMP Redirect messages (IPv4 type 5 and IPv6 type 137) sourced from internal RFC1918 addresses. ICMP Redirects are normally generated by on-path routers, so redirect messages from workstations or servers may indicate route manipulation for adversary-in-the-middle activity.

How To Test

RTA and shared data in stack.

Checklist

• Added a label for the type of pr: bug, enhancement, schema, maintenance, Rule: New, Rule: Deprecation, Rule: Tuning, Hunt: New, or Hunt: Tuning so guidelines can be generated
• Added the meta:rapid-merge label if planning to merge within 24 hours
• Secret and sensitive material has been managed correctly
• Automated testing was updated or added to match the most common scenarios
• Documentation and comments were added for features that require explanation

Contributor checklist

• Have you signed the contributor license agreement?
• Have you followed the contributor guidelines?

[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

• ❌ ICMP Redirect Message from Internal Host (kuery)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[Copilot]

Pull request overview

Adds a new network detection rule to identify ICMP Redirect messages originating from internal hosts, intended to highlight suspicious route manipulation consistent with Adversary-in-the-Middle activity.

Changes:

• Introduces a new KQL (kuery) rule targeting ICMP Redirect (IPv4 type 5 / IPv6 type 137) events in network_traffic.icmp.
• Adds an investigation guide, references, and MITRE ATT&CK mapping for Credential Access / Adversary-in-the-Middle.
• Configures rule metadata (indices, lookback window, severity/risk, tags, and timestamp_override).

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ ICMP Redirect Message from Internal Host (kuery)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[bryans3c]

Will the rule trigger FPs since there is no exclusion for legitimate redirects?

[eric-forte-elastic]

Generally speaking, yes there will likely be some FPs. However, the number would generally be based on whether or not one is using an internal IP address for en route redirects. This can happen, but is not standard. Given that, I expect the default would be to manage those cases with case by case exceptions, will the rule itself still providing value.

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ ICMP Redirect Message from Internal Host (kuery)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta