ModSecurity is a plugin for Apache web servers which functions as a web application layer firewall. It's employed to stop attacks against script-driven Internet sites through the use of security rules which contain specific expressions. This way, the firewall can block hacking and spamming attempts and shield even Internet sites that are not updated often. For instance, several failed login attempts to a script administrative area or attempts to execute a specific file with the purpose to get access to the script shall trigger specific rules, so ModSecurity will stop these activities the minute it detects them. The firewall is incredibly efficient as it monitors the entire HTTP traffic to a website in real time without slowing it down, so it will be able to prevent an attack before any harm is done. It additionally maintains an exceptionally comprehensive log of all attack attempts that features more info than standard Apache logs, so you could later analyze the data and take further measures to enhance the security of your sites if necessary.