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PASSEDserver / windows_defender_false_positive
Windows Defender False Positive Quarantining Production DLL
A Windows Defender signature update incorrectly identifies a critical production DLL as malware and quarantines it. The affected application fails to start, impacting all users of the ERP system.
Pattern
CLIENT_ERROR
Severity
CRITICAL
Confidence
95%
Remediation
Auto-Heal
Test Results
| Metric | Expected | Actual | Result |
|---|---|---|---|
| Pattern Recognition | CLIENT_ERROR | CLIENT_ERROR | |
| Severity Assessment | CRITICAL | CRITICAL | |
| Incident Correlation | Yes | 5 linked | |
| Cascade Escalation | N/A | No | |
| Remediation | — | Auto-Heal — Corax resolves autonomously |
Scenario Conditions
Windows Server 2022 running ERP application. Defender signature update 1.405.123.0 deployed. Custom DLL 'ERPCore.dll' flagged as Trojan:Win32/Generic. DLL quarantined from application directory. ERP application fails on startup.
Injected Error Messages (1)
ERP application failed to start — Windows Defender quarantined production DLL ERPCore.dll as Trojan:Win32/Generic (false positive), signature version 1.405.123.0, application cannot load required assembly, all ERP user sessions failing with module load error, defender real-time protection blocking restoration of quarantined file
Neural Engine Root Cause Analysis
The ERP application is failing to start because Windows Defender has quarantined the critical production DLL 'ERPCore.dll', falsely identifying it as Trojan:Win32/Generic. This is a false positive detection by Windows Defender signature version 1.405.123.0, preventing the application from loading required assemblies. The real-time protection feature is actively blocking attempts to restore the quarantined file, causing a complete service outage for all ERP users.
Remediation Plan
1. Temporarily disable Windows Defender real-time protection on the ERP server. 2. Restore ERPCore.dll from Windows Defender quarantine to its original location. 3. Add ERPCore.dll and the ERP application directory to Windows Defender exclusion list to prevent future false positives. 4. Restart the ERP application service. 5. Re-enable Windows Defender real-time protection. 6. Verify ERP application is accessible and functional. 7. Monitor for any additional quarantined files from the same application.
Tested: 2026-03-30Monitors: 1 | Incidents: 1Test ID: cmncjxxlr05okobqewid3i7fe