nkyre

WordPress upload file names can be quite predictable sometimes, especially if uploading from the same camera – DKIM1004 comes after DKIM1003. If not all of the content on your site is public, this can be a problem as people can snoop on your media folder by guessing file names.
This plugin prepends a short 8 character hash to the beginning of every uploaded file. For example, DKIM1004.jpg turns into 8df8078e-DKIM1004.jpg. The hash is not cryptographically secure and just makes it a bit more difficult to guess file names.
The plugin works on all upload file types and all sizes of a given image get the same prefix.

Media File Name Guess Preventer

Prepend a random string to media file uploads to prevent file name guessing.

Daniel Satria

Indonesia: Plugin ini akan menempatkan file index.html kosong di setiap folder dibawah wp-content/uploads untuk mencegah pencurian data. 
English: This is plugin will put empty index.html on every folders on wp-content/uploads to prevent content theft

Secure Folder wp-content/uploads

This is simple plugin to protect your wp-content/uploads folder from being browse & copy

Media File Name Guess Preventer vs Secure Folder wp-content/uploads