Limit Login Attempts with IP blocking, brute force protection, Google recaptcha on login as well as registration from spam protection, rename login url, XMLRPC etc.

Detect spam comments on WordPress site using Fortguard.

Security with firewall, malware scanner, login and spam protection, and encrypted backup. WP Security Plugin includes Login Security, Limit login attempts, Spam Protection, Content Protection, Blocking & more to Secure WordPress

Allows administrators to globally disable comments on their site. Comments can be disabled according to post type. Multisite friendly.