This batch file is pretty easy to understand and adapt if you re new to batch programming, once opened the computer will display several messages (which you can change easily) before shutting down the computer.
This will not harm your computer in anyway but before testing it make sure to save any work as you could lose it.
Step 1: The Code
Copy and paste this into the notepad app, you can change the text in bold caps to whatever you want.
Shutdown.exe /s /t 00
msg * MALWARE DETECTED!
msg * ANTIVIRUS FAIL!
msg * SYSTEM BREACH, SHUTDOWN COMMENCING!
Step 2: Save the File
Save the file as a bat file, to do this put .bat after the file name which can be whatever you want.