Public_Domain Public_Domain:
I am concerned that it deleted more than just fonts, but I'm not sure. For the most part the program gave me logs saying it couldn't touch system files. Fonts, sadly, are not 'protected', they are very easy to delete.
Something focused on deleting free space shouldn't even be anywhere near files....
I just did a CCleaner without any incident, so I think it's a bit more than just that program. You might have been remotely hacked and had those files deleted. Download Malwarebytes and Spyware Search&Destroy and do some full scans.