Log watchdog integrity failures and drift to the event log - #49
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The watchdog only wrote to a text file in %ProgramData%\Winnow, which a local attacker with access to that box can also edit, and which nothing collects centrally. For a control that runs as SYSTEM and fails closed on tampering, the tamper signal is the thing you most want auditable. Register a Winnow event source in the Application log at install and have the payload mirror its security-relevant lines there: an integrity failure as an Error (event 2000) and a corrected drift as a Warning (event 1000). Writing is guarded on the source existing and never throws, so a missing source just falls back to the text log. Added event-source-present and event-source-missing cases to the tests.
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What
The watchdog logged only to
%ProgramData%\Winnow\watchdog.log, a text file a local attacker on the box can also edit and that nothing collects centrally. For a control that runs as SYSTEM and fails closed on tampering, the tamper signal is exactly what you want auditable off-box.Winnowevent source in theApplicationlog (admin, already held; warns and continues if it can't).Write-WinnowWatchdogEventis guarded on the source existing (Test-WinnowWatchdogEventSource) and never throws; a missing source falls back to the text log alone. The text log still records everything, including intact runs.Validation
Tests\Invoke-StaticValidation.ps1 -RequirePSScriptAnalyzerclean (120 files).Tests/Unit/Test-UpdateWatchdog.ps1(Pester 5.7.1): 16/16 pass (adds source-present writes-once and source-missing stays-silent/no-throw).Not verified here (needs a live SYSTEM run against a real update): the actual event entries landing in the Application log. Docs (
docs/Telemetry-And-Privacy.md) and CHANGELOG[Unreleased]updated.