WordPress: Deactivate automatic plugin updates

deactivate-automatic-plugin-updates.php

<?php
/**
 * Plugin Name: Deactivate automatic plugin updates
 * Description: Deactivates the possibility to automatically update a plugin.
 * Plugin URI:  http://www.wp-sicherheit.info/
 * Version:     1.0
 * Author:      Marc Nilius
 * Author URI:  http://www.wp-sicherheit.info/
 * Licence:     GPL 2
 * License URI: http://opensource.org/licenses/GPL-2.0
 */

if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

// Add filter to not allow automatic plugin updates
add_filter( 'auto_update_plugin', '__return_false' );