score: reduce ELCEEF_Zombie_Malformed_ZIP quality to avoid FPs on Windows system files#82
Merged
Neo23x0 merged 1 commit intoYARAHQ:masterfrom Mar 17, 2026
Conversation
… (50) Daily FP test (2026-03-17) found 8 matches on Windows goodware: - MsSense.dll, SenseIR.exe, msedge.dll (Windows Defender/Edge) - SenseSampleUploader.exe, SenseDlpProcessor.exe, RunPsScript.dll Rule detects malformed ZIP structures, but these legitimate Microsoft binaries contain embedded archives that trigger the rule. Testing: Scanned against ~35GB goodware corpus including Win11 24H2 system files.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Daily false positive testing (2026-03-17) detected 8 matches on legitimate Windows goodware files.
Affected Files
The rule
ELCEEF_Zombie_Malformed_ZIPmatched on:MsSense.dll(Windows Defender)SenseIR.exe(Windows Defender Sensor)msedge.dll(Microsoft Edge)SenseSampleUploader.exe(Windows Defender)SenseDlpProcessor.exe(Windows Defender DLP)SenseTracer.exe(Windows Defender)RunPsScript.dll(Windows Defender)Root Cause
The rule detects malformed ZIP structures, but these legitimate Microsoft binaries contain embedded archives (likely for self-extraction or resource storage) that trigger the detection.
Changes
Testing