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.

Paolo T. (pixline)

swergroup

NEW: <a href="http://blog.sucuri.net/?p=7654" rel="nofollow ugc">EXIF header malware/backdoor</a> sanitization!
Filenames on the web are different than those on the desktop. Empty spaces and strange characters doesn’t belong to web space. Enter UploadPlus: you can set your rules and clean your files’ name while they upload. Three basic rules:
<ul>
<li>keep only alphanumeric [A-Za-z] and digits, spaces and strange characters stripped out;</li>
<li>convert spaces and strange characters into dashes (-)</li>
<li>convert spaces and strange characters in underscores (_)</li>
</ul>
You can apply website-based or date-based prefix, even a custom prefix. Lowercase or Uppercase? Your choice! 
Some default prefix:
<ul>
<li>time/date based timestamps via PHP date()</li>
<li>blog name/slug</li>
<li>random</li>
<li>and many more!</li>
</ul>
UploadPlus can also transliterate filenames (text conversion from a non-latin script to raw latin characters). 
You can preview settings in the media settings page without uploading files.
<h4>Support</h4>
We’ll do our best to support the plugin on <a href="https://wordpress.org/support/plugin/page2cat">support forum</a>. Paid support and custom coding options are available on the <a href="https://swergroup.zendesk.com" rel="nofollow ugc">SWERgroup HelpDesk</a>.
If you found this plugin useful or need a new feature feel free to <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=CX6VQ6FVJFN4L" rel="nofollow ugc">sponsor a coding/support session</a>!
<h4>Credits</h4>
GPL2© 2008+ Paolo Tresso/<a href="http://swergroup.com/sviluppo/siti-internet-torino/" rel="nofollow ugc">SWERgroup</a>.

UploadPlus : File Name Cleaner

Clean file names and enhance security while uploading.

Media File Name Guess Preventer vs UploadPlus : File Name Cleaner