Wordfence - Comprehensive security plugin for WordPress.
HackerOne - HackerOne provides a platform designed to streamline vulnerability coordination and bug bounty program by enlisting hackers.
iThemes Security - Security plugin that provides over 30+ ways to secure and protect your WordPress site.
Intruder - Intruder is a security monitoring platform for internet-facing systems.
NinjaFirewall (WP Edition) - A true Web Application Firewall to secure and protect WordPress.
Nessus - Nessus Professional is a security platform designed for businesses who want to protect the security of themselves, their clients, and their customers.