Swellfire

This plugin disables the XML-RPC API on a WordPress site running 3.5 or above and unsets the X-Pingback header.
Beginning in 3.5, XML-RPC is enabled by default. Additionally, the option to disable/enable XML-RPC was removed. For various reasons, site owners may wish to disable this functionality. This plugin provides an easy way to do so.

Disable XML-RPC & Unset X-Pingback

This plugin disables XML-RPC API in WordPress 3.5+, which is enabled by default.

Jonny Harris

Simple plugin that disables XML-RPC, since it is enabled by default on WordPress 3.5 and above. It also removed references in the headers and in the body of the html.
If you wish to follow the development of this plugin, view the code on the official plugin <a href="http://www.jonathandavidharris.co.uk/scripts/disable-xml-rpc-fully/" title="website" rel="nofollow ugc">website</a> or follow me on twitter <a href="https://twitter.com/thespacedmonkey" rel="nofollow ugc">@thespacedmonkey</a>

Disable XML-RPC & Unset X-Pingback vs Disable XML RPC Fully