[New Rule] Web Server Local File Inclusion Activity

[Aegrah]

Summary

This rule detects potential Local File Inclusion (LFI) activity on web servers by identifying HTTP GET requests that attempt to access sensitive local files through directory traversal techniques or known file paths. Attackers may exploit LFI vulnerabilities to read sensitive files, gain system information, or further compromise the server.

Telemetry

[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

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[eric-forte-elastic]

Note this error is due to the current validation stack being on version 9.1.* rather than 9.2 where URL_DECODE was introduced. The stack is being upgraded to allow for this function but a strategy is needed to verify these types of functions.

Error (EsqlTypeMismatchError): BadRequestError(400, 'verification_exception', 'Found 1 problem\nline 7:58: Unknown function [URL_DECODE]')
/home/runner/work/detection-rules/detection-rules/detection-rules/detection_rules/index_mappings.py:366: ElasticsearchWarning: Line 24:5: Field 'Esql.http_response_status_code_values' shadowed by field at line 28:5
  response = elastic_client.esql.query(query=query)
/home/runner/work/detection-rules/detection-rules/detection-rules/detection_rules/index_mappings.py:366: ElasticsearchWarning: Line 16:9: Field 'Esql.azure_signinlogs_properties_client_app_values' shadowed by field at line 17:9
  response = elastic_client.esql.query(query=query)
/home/runner/work/detection-rules/detection-rules/detection-rules/detection_rules/index_mappings.py:366: ElasticsearchWarning: Line 56:5: Field 'Esql.azure_signinlogs_result_description_values' shadowed by field at line 63:5
  response = elastic_client.esql.query(query=query)
90e4ceab-79a5-4f8e-879b-513cac7fcad9 Total rules: 79
Failed rules: 1
Failed rules written to failed_rules.log
Failed rule IDs:
90e4ceab-79a5-4f8e-879b-513cac7fcad9

[Mikaayenson]

nit: For attempts do we want to catch 403, 404, 500?

[Aegrah]

I don't want to find fuzzing activity. Effective LFI will most likely respond with 200.

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Web Server Local File Inclusion Activity (esql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta