Your files are not hidden, you have moved all files (and directories if any) one directory up.
This happens because mv * .* won't work as you think it will. The command mv will only move one file to one file (rename) or move one or multiple files to a directory. It won't move multiple files to multiple files with some smart renaming.
What happened?
Let's assume we have one directory and 3 files in our directory:
dir1
file1
file2
file3
Some Shells (e.g. bash, dash, ...) will expand your command to:
mv dir1 file1 file2 file3 . ..
Your expanded command fits the second form of the SYNOPSIS you find at man mv:
mv [OPTION]... SOURCE... DIRECTORY
Note the . and ..:
. is the current directory,.. is one directory up.
The command means: move dir1, file1, file2 and file3 and . to ..; It will also essentially give an error, something like:
mv: cannot move '.' to '../.'
But given you have write permission in that directory, all other files have been moved. You can find your files in .. (= one directory up). However, files with same name have been overwritten and you won't know which files was in which directory before.
If you had a subdirectory .hidden-dir, it would have expanded to:
mv dir1 file1 file2 file3 . .. .hidden-dir
Then, all files would have been moved to .hidden-dir. However, this seems not the case for you, because the you would have seen .hidden-dir in your ls -la output.
How to fix
Run:
mv ../dir1 ../file1 ../file2 ../file3 .
However, you need to know the names.
What you should have used
mmv '*' '.#1'
or
rename 's/^/./' *
Best Answer
Sure just reverse it:
The files has only changed its name. So you're fine in this case to simply rename it back.