ModSecurity is a plugin for Apache web servers that acts as a web application layer firewall. It is employed to stop attacks towards script-driven websites by using security rules that contain specific expressions. In this way, the firewall can stop hacking and spamming attempts and protect even websites that are not updated frequently. For example, several failed login attempts to a script administrator area or attempts to execute a particular file with the purpose to get access to the script shall trigger certain rules, so ModSecurity shall block out these activities the instant it discovers them. The firewall is incredibly efficient because it monitors the whole HTTP traffic to an Internet site in real time without slowing it down, so it can prevent an attack before any damage is done. It furthermore keeps an incredibly thorough log of all attack attempts that features more info than conventional Apache logs, so you can later check out the data and take additional measures to improve the security of your websites if required.