screen goes blank and cursor still moves,

If the screen is blank how are you able to post here?

Doesn't sound to me like you've been hacked. Have you shut down the computer and restarted? There is a difference between shut down and restart.

With Shut Down, Windows 10 shuts down all programs and files you have open, but doesn't shut off the Windows kernel – that is, the core of the operating system, which enables the software and the hardware to work together, the Windows kernel is saved to disk, similar to when you put your computer to hibernation mode, so that the kernel is ready to boot up quickly the next time.

Restart, in contrast, actually does shut down all of the computer's processes, including the kernel. That means you get a totally clean start when the computer boots up again, though it takes longer to get everything running.
Do the restart and see if that helps. 

When this happened were you touching the mouse at all or was your hand 100% away from the mouse or touch pad?

When you said you shut the computer off and restarted did you actually choose RESTART or did you just choose shut down and then manually turned it back on?

Your description of your shut down does not sound to me like you actually did a full restart. I asked you if you MANUALLY turned the computer back on and if this is what you did then you did not do the restart.
I don't know what operating system you are using, I asked on another thread but you didn't say.
When you are going to RESTART the computer you choose RESTART not Shut down. You hit RESTART and the computer does all of the work iself. It shuts down and then Restarts on its own...is this what you did? 
Restart clears out everything and then everything, all background processes all restart anew. 

You still have not told me the operating system. Dell is the manufacturer, the Microsoft browser is just that, a browser called EDGE. The operating system is likely either Windows 10 or Windows 11.

Now, you do not need to always restart, only when you either have done an update and Windows Update says it is required, then it will be generally be done automatically. The onlly other time is when you are having a problem.