There's a vulnerability in WordPress's XMLRPC implementation, that permits trackback spam - even when you disable trackbacks.
The only way to prevent this spam is to disable XMLRPC entirely. Some people have suggested renaming or deleting the xmlrpc.php file, but this is not a good idea, because it's altering core code and not trivial for novice users to undo.
This plugin completely disables WordPress's XMLRPC functions, and doesn't alter or rename any core files. You can enable XMLRPC again by simply disabling this plugin.
See http://www.acunetix.com/blog/web-security-zone/wordpress-pingback-vulnerability/ for detailed information about the vulnerability in WordPress's XMLRPC handler.
IP Geo Block
There are some cases of a site being infected. The first one is the case
that contaminated files are uploaded via FTP or some kind of uploaders.
In this case, scaning and verifing integrity of files in your site is useful
to detect the infection.
The second one is cracking of the login username .........
WP-Hashcash
No More Spam
WP Hashcash is an antispam plugin that eradicates comment spam on WordPress blogs. It works because your visitors must use obfuscated javascript to submit a proof-of-work that indicates they opened your website in a web browser, not a robot. If the javascript check fails, WP Hashcash n.........
WP-Hashcash Extended
No More Spam
WP Hashcash is an antispam plugin that eradicates comment spam on WordPress blogs. It works because your visitors must use obfuscated javascript to submit a proof-of-work that indicates they opened your website in a web browser, not a robot. If the javascript check fails, WP Hashcash n.........
Power Menus
Secure your WordPress login form from bruteforce attacks and bots in a click! Just install the plugin, activate and relax ;)...
Notifier and IP Blocker
Notifier and IP Blocker is a simple plugin that can secure your web-site from spam bots and notify users. The many users, who write a comment want to know, whether the administrator had got it or not. Send a message where it is written that the comment had been received and the answer would be sent .........
Exploitify WordPress Security
The fastest way to stop botnets and spammers from attacking your WordPress website.
Block IP addresses of known botnets from accessing your site. Stop requests with no UserAgent, and mitigate spam comments and registration. As of July 2015, database consists of over 1.1M IP and 2.4M email addresses.........
WP Block Referrer Spam
Keep your WordPress site safe and away from referrer spam attacks!
Not compatible with multisite yet
This plugin blocks spam sites and referrer spammers from reaching your website, keeping your Google Analytics statistics clean and accurate. It also improves the overall performance of your site by.........
Clean Up Booster - Optimize DB & WordPress
Clean Up Booster is a Superlative High quality WordPress Plugin which allows you to clean up the WordPress Database.
The following things should be clean with the Clean Up Booster, which are mentioned below:
Auto Drafts
Dashboard Transient Feed
Unapproved Comments
Orphan Comments Meta
Orphan Post.........
WP-SpamShield Anti-Spam
An exceptionally powerful and user-friendly WordPress anti-spam plugin that eliminates comment spam, trackback spam, contact form spam & registration spam....
BulletProof Security
BulletProof Security Feature Highlights
One-Click Setup Wizard
jQuery UI Dialog Form Uninstall Options: BPS Pro upgrade uninstallation or complete BPS plugin uninstallation
.htaccess Website Security Protection (Firewalls)
Login Security & Monitoring
Idle Session Logout (ISL)
Auth Cookie Expir.........
