There's a task in Windows Task Scheduler called "SilentCleanup" which, while it's executed as Users, automatically runs with elevated privileges. When it runs, it executes the file %windir%\system32\cleanmgr.exe. Since it runs as Users, and we can control user's environment variables, %windir% (normally pointing to C:\Windows) can be changed to point to whatever we want, and it'll run as admin.
To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':
Time is precious, so I don’t want to do something manually that I can automate. Leveraging the Metasploit Framework when automating any task keeps us from having to re-create the wheel as we can use the existing libraries and focus our efforts where it matters.
– Jim O’Gorman | President, Offensive Security