Sucuri Intrusion Detection System (IDS) by Sucuri protects websites against malicious code with its Web Application Firewall (WAF). It provides zero-day exploit prevention, DDoS attack mitigation, and brute force protection. Sucuri IDS constantly updates patches and server rules to protect websites from emerging security threats. It inspects all HTTP/HTTPS web traffic before reaching the server, blocking malicious requests and attack patterns using heuristic and signature-based techniques. Sucuri IDS also includes features like virtual patching and hardening, which help secure websites even when security patches cannot be applied immediately. The system allows for the restriction of admin access to allowlisted IP addresses and adds another layer of protection to sensitive pages with passwords, CAPTCHA, 2FA, or IP allowlisting. It also blocks visitors from the top three attack countries with one click or allows users to choose which countries to block.