just install the "extra" JA Multiple Captcha Engine Plugin  and can officially say goodbye to the evil spammers.

Your /administrator area is vulnerable - secure it with AdminExile. Access keys, IPv4/6 Black/White Lists (IP and CIDR netmasks supported), Brute Force detection. AdminExile has you covered.

A lightweight jQuery notification plugin that displays a fully customizable cookie alert popup to make your website compliant with the EU Cookie Law.
- Easy to Use.
- Responsive.
- Customizable: Many different colors and options available.

Ruxin Login Notification is a great plugin that notifies you via email when someone logged in to your site.
- Ability to ignore user groups.
- Ability to ignore specific user.
- Send the IP, username, ID and login time to your email after user login.

Additional Link: Country Block Tutorial

Want to restrict or block someone from certain countries accessing your Joomla web site? Country Block module is the answer.

CountryBlock, a Joomla Module, is designed to offer your maximum flexibility to control where and how to restrict visitors based on their countries. In addition, it can be

jSecure Authentication was developed and published in 2008 and has been a widely used security extension that empowers multi-layered security protection to your Joomla website. It is an advanced security extension that intercepts unethical hacking attacks and provides all-round protection to your site. The simple user interface is designed to make admin use all the parameters with easy and without having any detailed technical skills. Our expert team of developers keeps

Keep your forms spam free with user friendly Captcha alternatives.

Right Click Disable is an extension which can help you to disable visitors or users to right click on your page which can help you to protect your content from directly being copied.

Most hacker attacks are preventable. Instantly protect your website from most attacks with jomDefender, a must-have first line of defense for every Joomla-powered website.

Lock Any Content and Increase Your User 

Article Content locker is a content plugin. It's lock content Immediate or after sometime when user read the article. The Article content locker helps you to increase your site users. The login coming with modal when a user click the button.

PWT ACL - formally known as ACL Manager - makes Joomla ACL easy to understand and manage. It provides a great overview of all Joomla ACL settings and will detect & fix issues with the Joomla assets table easily.

This plugin follows your site. Saving and displaying all unsuccessful login with all details including date, user IP, country, encrypted password, operating system and browser in a database. It can also inform you by email that someone with the username and password you intended to log in to your site has been unsuccessful.

Securitycheck Pro Control Center has been designed with one goal: to make Joomla administrator's life easier. Manage all your Joomla websites from a centralized console: launch remote tasks, make backups, install extensions remotely, update your extensions and even the Joomla core easily