I haven't visited this site in many, many moons but stopped by to take a look and discovered your problem.

If you are using a WD external drive for system back up...these files may be related to it. They may be your backup files. I use WD's MyPassport but don't have it permanently attached to my system. I didn't want some of the pesky problems that it can cause...and most recently, their latest version is causing some people unwanted headaches.

My suggestion...check your Device Manager and see if WD is listed as a communication device. It probably hasn't had its driver activated. Activate the driver and it should help eliminate your problem. Or...do what I do and manually run a back-up whenever you want.

Good luck.