Naxsi - NAXSI means Nginx Anti XSS & SQL Injection.
CloudFlare - Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.
ModSecurity - ModSecurity is an Open Source web application firewall developed by Trustwave's SpiderLabs.
Myra Security - The Myra Security-as-a-Service platform monitors, analyzes, and filters malicious internet traffic before virtual attacks can do any real harm.
CloudLayar - CloudLayar.com provides 100% Free DDoS Protection service from bots, crawlers, spiders, malware scanners and port scanners. Simply add your domain!
AWS WAF - AWS WAF is a web application firewall that helps protect your web applications from common web exploits.