Just a thought...
Some of the rogue malware progams HIDE (or MOVE) your personal files, placing them in "temporary" areas. Your desktop appears empty, as if everything is gone. IF that's what happened here, it may be possible, under guidance, to recover them... AS LONG AS you don't run any "temp file cleaners" (such as Disk Cleanup or CCleaner).
Typically, such a rogue program would have alerted you, either claiming to have found lots of errors on your system... perhaps even asserting it was about to crash... and offering to "fix" everything for you... for a FEE. Sometimes, they explicitly make a "ransom" demand, telling you they've encrypted all your files, and that you must pay them to get your files back. If you didn't experience either of these symptoms, then my "thought" might not apply to what happened to you.
regardless, I would NOT run any "temp file cleaners" until you're sure it won't permanently impact your system in a negative way.