Create a Shortcut to Abort Shutdown

If any rouge application tries to restart your PC, with a shutdown countdown timer. You can abort that shutdown with a code that execute from Start - Run

The Shutdown aborting code is
" shutdown -a "

You also can create Desktop shortcuts to abort shutdown

Right Click on Desktop and Select New - Shortcut

In Path
Type : shutdown.exe -a

and click Next, Write a name like, " Abort Shutdown ".

When your PC Starts to Shutdown open this shortcut to stop shutdown process.