How to Tweak wp-config.php to Protect Your WordPress Site
If you think your site is safe because it doesn’t have any content worthwhile to hackers, think again, because the vast majority of security breaches aren’t aimed at stealing your data or defacing your site. Hackers generally want to use your server as an email relay for spam, or to setup a temporary web server, usually to serve illegal files. If you’re hacked, get ready to shell out money for soaring server costs.
Source: How to Tweak wp-config.php to Protect Your WordPress Site