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@w0rk3r w0rk3r commented Aug 28, 2025

Summary

Adjusts the Crowdstrike paths to account for when \\Device\\HarddiskVolume is followed by more than one digit.

@w0rk3r w0rk3r self-assigned this Aug 28, 2025
@w0rk3r w0rk3r added Rule: Tuning tweaking or tuning an existing rule OS: Windows windows related rules Domain: Endpoint backport: auto labels Aug 28, 2025
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Rule: Tuning - Guidelines

These guidelines serve as a reminder set of considerations when tuning an existing rule.

Documentation and Context

  • Detailed description of the suggested changes.
  • Provide example JSON data or screenshots.
  • Provide evidence of reducing benign events mistakenly identified as threats (False Positives).
  • Provide evidence of enhancing detection of true threats that were previously missed (False Negatives).
  • Provide evidence of optimizing resource consumption and execution time of detection rules (Performance).
  • Provide evidence of specific environment factors influencing customized rule tuning (Contextual Tuning).
  • Provide evidence of improvements made by modifying sensitivity by changing alert triggering thresholds (Threshold Adjustments).
  • Provide evidence of refining rules to better detect deviations from typical behavior (Behavioral Tuning).
  • Provide evidence of improvements of adjusting rules based on time-based patterns (Temporal Tuning).
  • Provide reasoning of adjusting priority or severity levels of alerts (Severity Tuning).
  • Provide evidence of improving quality integrity of our data used by detection rules (Data Quality).
  • Ensure the tuning includes necessary updates to the release documentation and versioning.

Rule Metadata Checks

  • updated_date matches the date of tuning PR 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. Review to ensure the original intent of the rule is maintained.

Testing and Validation

  • Validate that the tuned rule's performance is satisfactory and does not negatively impact the stack.
  • Ensure that the tuned rule has a low false positive rate.
@tradebot-elastic
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tradebot-elastic commented Aug 28, 2025

⛔️ Test failed

Results
  • ✅ Execution of COM object via Xwizard (eql)
  • ❌ UAC Bypass via DiskCleanup Scheduled Task Hijack (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Adobe Hijack Persistence (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Program Files Directory Masquerading (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ✅ Microsoft Exchange Server UM Spawning Suspicious Processes (eql)
  • ❌ Microsoft Management Console File from Unusual Path (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Execution via Windows Command Debugging Utility (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Execution via Windows Subsystem for Linux (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Suspicious Execution from INET Cache (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Attempt to Install Kali Linux via WSL (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
@tradebot-elastic
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tradebot-elastic commented Aug 28, 2025

⛔️ Test failed

Results
  • ✅ Execution of COM object via Xwizard (eql)
  • ❌ UAC Bypass via DiskCleanup Scheduled Task Hijack (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Adobe Hijack Persistence (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Bypass UAC via Event Viewer (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Program Files Directory Masquerading (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ✅ Microsoft Exchange Server UM Spawning Suspicious Processes (eql)
  • ❌ Microsoft Management Console File from Unusual Path (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Signed Proxy Execution via MS Work Folders (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Execution via Windows Command Debugging Utility (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Execution via Windows Subsystem for Linux (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Suspicious Execution from INET Cache (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Attempt to Install Kali Linux via WSL (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
@tradebot-elastic
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tradebot-elastic commented Aug 29, 2025

⛔️ Test failed

Results
  • ✅ Execution of COM object via Xwizard (eql)
  • ❌ UAC Bypass via DiskCleanup Scheduled Task Hijack (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Adobe Hijack Persistence (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Bypass UAC via Event Viewer (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Program Files Directory Masquerading (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ✅ Microsoft Exchange Server UM Spawning Suspicious Processes (eql)
  • ❌ Microsoft Management Console File from Unusual Path (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Signed Proxy Execution via MS Work Folders (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Execution via Windows Command Debugging Utility (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Execution via Windows Subsystem for Linux (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Suspicious Execution from INET Cache (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Attempt to Install Kali Linux via WSL (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
@tradebot-elastic
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tradebot-elastic commented Sep 1, 2025

⛔️ Test failed

Results
  • ✅ Execution of COM object via Xwizard (eql)
  • ❌ UAC Bypass via DiskCleanup Scheduled Task Hijack (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Adobe Hijack Persistence (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Bypass UAC via Event Viewer (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Program Files Directory Masquerading (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ✅ Microsoft Exchange Server UM Spawning Suspicious Processes (eql)
  • ❌ Microsoft Management Console File from Unusual Path (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Signed Proxy Execution via MS Work Folders (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Execution via Windows Command Debugging Utility (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Execution via Windows Subsystem for Linux (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Suspicious Execution from INET Cache (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Attempt to Install Kali Linux via WSL (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
@tradebot-elastic
Copy link

tradebot-elastic commented Sep 1, 2025

⛔️ Test failed

Results
  • ✅ Execution of COM object via Xwizard (eql)
  • ❌ UAC Bypass via DiskCleanup Scheduled Task Hijack (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Adobe Hijack Persistence (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Bypass UAC via Event Viewer (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Program Files Directory Masquerading (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ✅ Microsoft Exchange Server UM Spawning Suspicious Processes (eql)
  • ❌ Microsoft Management Console File from Unusual Path (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Signed Proxy Execution via MS Work Folders (eql)
    • stack_validation_failed: no_alerts - 0 alerts
  • ❌ Execution via Windows Command Debugging Utility (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Execution via Windows Subsystem for Linux (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Suspicious Execution from INET Cache (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
  • ❌ Attempt to Install Kali Linux via WSL (eql)
    • coverage_issue: no_rta
    • stack_validation_failed: no_rta
@w0rk3r w0rk3r merged commit b2bc602 into main Sep 1, 2025
12 checks passed
@w0rk3r w0rk3r deleted the cs_paths branch September 1, 2025 12:31
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Labels

backport: auto Domain: Endpoint OS: Windows windows related rules Rule: Tuning tweaking or tuning an existing rule

4 participants