Malicious DLL Side-Loading by 3CX Desktop Application (via image_load)

ATT&CK techniques

Initial Access → Defense Evasion

Recon
Resource Dev
Initial Access
- T1195.002Compromise Software Supply Chain
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 the 3CX desktop application loading ffmpeg.dll or d3dcompiler_47.dll from its own directory, the side-loading chain used in the supply chain compromise. The trojanized ffmpeg first stage and d3dcompiler decryptor run under the trusted signed 3CX process to stage second-stage shellcode.

Reporting behind it

Related detections9 linkedT1574.001 — drag to rearrange

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Malicious DLL Side-Loading by 3CX Desktop Application (via image_load)

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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