indextwo

Whenever WordPress performs a core update, it automatically pulls down the following files onto the root:
<ul>
<li><code>license.txt</code></li>
<li><code>readme.html</code></li>
<li><code>wp-config-sample.php</code></li>
</ul>
These files aren’t an inherent security risk by themselves; however they are uneccessary clutter on the root of your site (why would you want a <code>wp-config-sample.php</code> file on your production website?!); and it’s just another easy-to-read vector confirming that you have a WordPress site for script-kiddies to scrape and attack.
Simply install this plugin and it will clean up those files every time you perform a core WordPress update.

Core Files Update Cleanup

This plugin deletes the unnecessary license.txt, readme.html and wp-config-sample.php files after a core update.

Yslo

WordPress, by default, allows you the ability edit theme and plugin files directly from within the WordPress control panel.
If you never change files directly on your WordPress site, there’s absolutely no need to have this feature available to you or your administrators.
<h4>Features</h4>
<ul>
<li>Disable WordPress Theme/Plugin Editor</li>
</ul>

WP Theme Plugin Editor Disable

This plugin disable Wordpress Theme/Plugin Editor.

Core Files Update Cleanup vs WP Theme Plugin Editor Disable