Malicious Rundll32 Execution Of HTML Payload With DllRegisterServer

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218.011Rundll32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects rundll32 loading a file with an .html extension and calling the DllRegisterServer export, the disguised DLL execution used in the Zloader attack against Intel 471. Masquerading the DLL as an HTML file evades extension-based inspection while rundll32 still runs it as a library. This mismatch of extension and export is a strong loader indicator.

Reporting behind it

Related detections9 linkedT1218.011 — drag to rearrange

Malicious Rundll32 Loading an Export From a User Path (via process_creation)

Renamed Regsvr32 or Rundll32 Loading a DLL With a Non-Standard Extension (via process_creation)

Malicious Rundll32 DllRegisterServer Execution From a User-Writable Path (via process_creation)

IMEEX Framework DLL Execution via Rundll32 Loading imaadp (via process_creation)

Suspicious Persistence via pcalua Launching rundll32 Control_RunDLL

Suspicious Rundll32 Executing DLL Start Export With Control Flags

Suspicious Rundll32 Execution of Timestamp-Named DLL

Suspicious Rundll32 Loading DLL from LocalAppData with Short Export (via process_creation)

Malicious Word Spawning Rundll32 Loading DLL from Roaming Word Folder

Malicious Rundll32 Execution Of HTML Payload With DllRegisterServer

Pivot detection · T1218.011 · 9 related

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