Windows Defender Threat Detected on Kernel Object Path
Description
The following analytic detects a Windows Defender malware detection or remediation event where the scanned path resolves through the NT object manager namespace (\globalroot\). It leverages Windows Defender Operational log EventCodes 1116 and 1117 to identify this activity. In the ShieldBreak exploit, this is how Defender is coerced into hydrating a cloud file placeholder and copying attacker content through a symbolic link chain that ultimately writes into C:\Windows\System32. If confirmed malicious, this activity indicates an attempt to weaponize Windows Defender's own scanning pipeline for local privilege escalation.
Query · spl
`ms_defender`
EventCode IN (1116, 1117)
Path="*\\globalroot\\*"
| fillnull
| stats count min(_time) as firstTime
max(_time) as lastTime
values(EventCode) as EventCode
values(Action_Name) as Action_Name
values(Additional_Actions_String) as Additional_Actions_String
values(FWLink) as FWLink
by dvc Detection_User Path Threat_Name Severity_Name Category_Name
| rename dvc as dest, Detection_User as user
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_defender_threat_detected_on_kernel_object_path_filter`
Implementation guide
The following analytic requires collection of Windows Defender Operational logs in either XML or multi-line, via the Splunk Add-on for Microsoft Windows. Ensure the Microsoft-Windows-Windows Defender/Operational channel is being collected so that EventCode 1116 (detection) and 1117 (remediation) events are ingested.
Known false positives
- No false positives have been identified at this time. Legitimate Defender scans do not report detections against paths resolved through the NT object manager namespace.
Analyst notes
Known false positives: No false positives have been identified at this time. Legitimate Defender scans do not report detections against paths resolved through the NT object manager namespace.