Sorting thought courpt file (cyptovirus)

Someone at the place i work got a cryptovirus. Lucky it only affected one persons stuff.
I can recover the network file from incremental backup but not the flash drive where most of the work was saved.

I am looking to see if i can salvage some stuff by doing a hard drive recovery.(if the program created the encrypted files then deleted the old).

But now i have thousands of files recovered but most of them are old and partially overwritten. Is there a way i can automatically sort thought this crap and see only good word and excel documents.

The We were able to narrow down the list by date but the person still had to sort though about 1000 unnamed files. I was surprised the maker of the virus didn't consider someone could recover data by disk recovery.