WordPress being the most-used Content Management System worldwide, a lot of people are searching for holes in its security. Luckily, the WordPress development team is making an amazing job at keeping all of our blogs safe, as long as we keep downloading and installing upgrades.
Whenever someone (you or anyone else) tries to log into your WordPress blog but fails, WordPress displays an error message to let you know what just happened. While it may be useful for you, it may also give some information to potential blog hackers who are trying to break into your blog.
To improve your WordPress blog, an interesting step you can take is disabling these messages. To do so, simply paste the following code in the functions.php of your WordPress blog:
add_filter('login_errors',create_function('$a', "return null;"));