Unidentified files

We have unidentifed files appearing on our Windows File Shares which have no file extension and are just numeric eg. eg. 5C458200, EC593000. These files appear randomly of different file size (although none larger than the standard 4gb for an NTFS file)The files are always named in an 8 character-long, upper-case format – the last two characters are always two zeros and have no association with them.There is no way of finding out who created them.