Can't Stop Backup Process

I have a process whereby I was trying to backup a second NAS drive onto an external drive connected to my computer. I already did this with my first NAS drive. I can't get the second one to finish...so I stopped bothering with it for a couple of weeks. I'm come back to start a different process entirely on other drives and find that the one I created for the second NAS drive won't stop.

This time around, I realized my NAS wasn't even turned on, so I thought, well, turn it on and let it do it's thing for a few minutes and then stop the process. It won't let me. It keeps trying to do the backup. I can't stop it, delete it, change it, nor even start the unrelated process I was going after, today, in the first place.

Thoughts?