Wordfence - Comprehensive security plugin for WordPress.
Sucuri - Website Protection, Malware Removal, and Blacklist Prevention
Shield Security - The most advanced and easy-to-use WordPress security plugin.
Webtotem - Free security & monitoring platform for websites
Acunetix - Audit your website security and web applications for SQL injection, Cross site scripting and other...
WebARX - Website Protection, Managed Website Security & Website Monitoring