iThemes Security - Security plugin that provides over 30+ ways to secure and protect your WordPress site.
Sucuri - Website Protection, Malware Removal, and Blacklist Prevention
Virusdie - All-in-One cloud-based, simple, powerful and gorgeous website security tools built for everyone.
Yoast Plugins - Yoast offers plugins to improve SEO and optimize web sites and blogs.
WP Rocket - WP Rocket offers a caching plugin for Wordpress.
WebARX - Website Protection, Managed Website Security & Website Monitoring