Acunetix - Audit your website security and web applications for SQL injection, Cross site scripting and other...
Wordfence - Comprehensive security plugin for WordPress.
Horangi - Horangi is a leading cyber-security solution that provides instant response and threat detection for companies who lack the time and expertise to monitor their system.
iThemes Security - Security plugin that provides over 30+ ways to secure and protect your WordPress site.
PracticeProtect - Network security & identity management
Sucuri - Website Protection, Malware Removal, and Blacklist Prevention