ishitaka

XO Security is a plugin to enhance login related security. 
This plugin does not write to .htaccess file. Besides Apache, LiteSpeed, Nginx and IIS also work.
<h4>Functions</h4>
<ul>
<li>Record login log.</li>
<li>Limit login attempts.</li>
<li>Add Captcha to the login form and comment form.</li>
<li>Change the URL of the login page.</li>
<li>Enable two-factor authentication (2FA) for login.</li>
<li>Login Alert.</li>
<li>Disable login by mail address.</li>
<li>Disable login by user name.</li>
<li>Change login error message.</li>
<li>Disable XML-RPC and XML-RPC Pingback.</li>
<li>Disable REST API.</li>
<li>Disable author archive page.</li>
<li>Remove comment author class of comments list.</li>
<li>Remove the username from the oEmbed response data.</li>
<li>WooCommerce login page protection.</li>
<li>Anti-spam comment.</li>
<li>Hide WordPress version information.</li>
<li>Edit the author slug.</li>
<li>Disable RSS and Atom feeds.</li>
<li>Activate maintenance mode.</li>
<li>Delete the readme.html file.</li>
</ul>
<h4>WordPress multisite considerations</h4>
If you set the login page separately for the main site and the subsite, you will not be able to use the password loss function of the subsite. We recommend that you set the login page to be common to all sites.

XO Security

This is awesome plugin!
It has all the features I need and is very easy to use.

Awesome!

長年、SiteGuardを使っていましたが、たまにログインできなくなってプラグインをサーバーから削除とかしたりだったので、こちらのプラグインを使い始めました。
設定画面もわかりやすく、作動も安定していて、ログイン試行履歴とかも見れます（結構不正ログインされようとしているのがわかって楽しい）、随時他のサイトのセキュリティプラグインもこちらに切り替えていこうと思っています。感謝感謝

とても良い


This one plugin completes my security measures. Thanks !!


This one is all you need !


It's my top recommendation for security plugins on WordPress sites.It includes all the security features I need.


What a great plugin!


This plugin is lightweight and easy to use, so I recommend it.


XO Security is a plugin to enhance login related security.

Amin Nazemi

Neatma

Protect your website from xmlrpc brute-force attacks,DOS and DDOS attacks, this plugin disables the XML-RPC and trackbacks-pingbacks on your WordPress website.
PLUGIN FEATURES 
(These are options you can enable or disable each one)
<ul>
<li>Disable access to xmlrpc.php file using .httacess file </li>
<li>Automatically change htaccess file permission to read-only (0444)</li>
<li>Disable X-pingback to minimize CPU usage </li>
<li>Disable selected methods from XML-RPC</li>
<li>Remove pingback-ping link from header</li>
<li>Disable trackbacks and pingbacks to avoid spammers and hackers</li>
<li>Rename XML-RPC slug to whatever you want</li>
<li>Black list IPs for XML-RPC</li>
<li>White list IPs for XML-RPC</li>
<li>Some options to speed-up your wordpress website</li>
<li>Disable JSON REST API</li>
<li>Hide WordPress Version</li>
<li>Disable built-in WordPress file editor</li>
<li>Disable wlw manifest</li>
<li>And some other options</li>
</ul>
What is XMLRPC
XML-RPC, or XML Remote Procedure Call is a protocol which uses XML to encode its calls and HTTP as a transport mechanism. 
Beginning in WordPress 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.
Why you should disable XML-RPC 
Xmlrpc has two main weaknesses
<ul>
<li>Brute force attacks: 
Attackers try to login to WordPress using xmlrpc.php with as many username/password combinations as they can enter. A method within xmlrpc.php allows the attacker to use a single command (system.multicall) to guess hundreds of passwords. Daniel Cid at Sucuri described it well in October 2015: “With only 3 or 4 HTTP requests, the attackers could try thousands of passwords, bypassing security tools that are designed to look and block brute force attempts.”</li>
<li>Denial of Service Attacks via Pingback: 
Back in 2013, attackers sent Pingback requests through xmlrpc.php of approximately 2500 WordPress sites to “herd (these sites) into a voluntary botnet,” according to Gur Schatz at Incapsula. “This gives any attacker a virtually limitless set of IP addresses to Distribute a Denial of Service attack across a network of over 100 million WordPress sites, without having to compromise them.”</li>
</ul>

Disable XML-RPC-API

The upgrade notice keeps coming back on every screen even after being dismissed. It looks very unprofessional to my clients and is embarrassing for me as a web developer, i would rather disable the plugin and use the code in a function. 

It should be permanently dismissible via a cookie, like for other plugins. It might be ok once, when the plugin is first installed or updated, but after that, it should never appear again. 

Good plugin, but upgrade nag is too annoying

A simple and lightweight plugin to disable XML-RPC API, X-Pingback and pingback-ping in WordPress 3.5+ for a faster and more secure website

XO Security vs Disable XML-RPC-API