To hide a folder from FTP, use NTFS permissions.
To hide a folder:
1. Remove the Everyone group permissions.
2. Add the Administrators group with Full Control.
3. Set the Anonymous User permissions to Special Directory Access and click Other in the Special Directory Access dialog box. Do not have any other boxes checked.
With the above permissions, an anonymous FTP user will receive an Access Denied when trying to
gain access to the folders file list, but they can retrieve a known file name with the full URL.