Sucuri Security is a security plugin for WordPress. This plugin is from the popular website security and auditing company Sucuri.
This plugin offers various security features like security activity auditing, file integrity monitoring, malware scanning, blacklist monitoring, and website firewall. It incorporates various blacklist engines including Google Safe Browsing, Sucuri Labs, Norton, McAfee Site Advisor and more to check your site. If there is anything wrong, it will notify you via email.