Malicious DLL Sideloaded by Microsoft Office Application

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1574.001DLL
Persistence
- T1574.001DLL
Priv Esc
- T1574.001DLL
Defense Evasion
- T1574.001DLL
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a Microsoft Office application loading one of the specific DLLs abused for the MS15-132 DLL hijack such as elsext dll oci dll and the winrt forwarder library as described in NCC Group Office DLL hijacking research. Adversaries deliver a document with an OLE object via the browser that drops a malicious DLL next to the document so Office resolves and executes attacker code for initial access.

Reporting behind it

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Malicious DLL Sideloaded by Microsoft Office Application

Pivot detection · T1574.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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