How is an IIS module registered and installed on a server, and what privileges are required?

An IIS module can be registered via the APPCMD.EXE command-line tool (e.g., `APPCMD.EXE install module /name:test /image:"c:\test\IIS-Backdoor.dll" /add:true`), through the IIS Manager GUI by navigating to Modules -> Configure Native Modules -> Register, or by manually editing `applicationHost.config` or `web.config`. Administrator privileges are required for installation, as the module must be loaded into the IIS worker process. Once registered, the backdoor becomes persistent and active after an IIS restart.