[Rule Tuning] Windows Misc Tunings

[w0rk3r]

Issues

Resolves #6228
Resolves #6016

Summary

Excludes FP Patterns, fix a typo.

[github-actions]

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]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[Copilot]

Pull request overview

This PR tunes multiple Windows detection rules to reduce false positives and correct minor issues, aligned to the linked tuning issues (#6228, #6016).

Changes:

• Adjusted EQL logic in PPID spoofing and unusual parent/child relationship rules to suppress additional benign patterns.
• Expanded allowlists in the Kerberos correlation rule and added a new benign driver hash exclusion.
• Fixed a typo in the ScreenConnect child-process rule (bitsadmin).

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
rules/windows/privilege_escalation_via_ppid_spoofing.toml	Adds new allowlist logic for accessibility utilities and extends a Netwrix-related exclusion.
rules/windows/privilege_escalation_unusual_parentchild_relationship.toml	Adds new false-positive suppressions (WER rundll32 pattern, 4688 SID-like parent name).
rules/windows/lateral_movement_credential_access_kerberos_correlation.toml	Adds additional benign process paths to the Kerberos correlation allowlist.
rules/windows/defense_evasion_untrusted_driver_loaded.toml	Adds a new SHA256 exception (test-signed driver) and adjusts comment placement.
rules/windows/command_and_control_screenconnect_childproc.toml	Fixes bitsadmin.exe typo in the suspicious child process list.

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[Samirbous]

any noisy FPs worth excluding for this rule?

[w0rk3r]

I see a high volume for C:\WINDOWS\SystemTemp\ScreenConnect\<version>\<random>run.cmd, but I need to validate whether this is for updates only or for script execution. Will do that as part of https://github.com/elastic/ia-trade-team/issues/984

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

Will rereview

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta

[tradebot-elastic]

⛔️ Test failed

Results

• ❌ Privileges Elevation via Parent Process PID Spoofing (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Unusual Parent-Child Relationship (eql)
  • stack_validation_failed: no_alerts - 0 alerts
• ❌ Suspicious ScreenConnect Client Child Process (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Suspicious Kerberos Authentication Ticket Request (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta
• ❌ Untrusted Driver Loaded (eql)
  • coverage_issue: no_rta
  • stack_validation_failed: no_rta