ModSecurity is a highly effective web application layer firewall for Apache web servers. It monitors the entire HTTP traffic to a site without affecting its operation and when it detects an intrusion attempt, it prevents it. The firewall additionally maintains a more thorough log for the traffic than any server does, so you shall be able to keep track of what's going on with your sites a lot better than if you rely only on standard logs. ModSecurity works with security rules based on which it prevents attacks. For instance, it recognizes whether anyone is attempting to log in to the admin area of a certain script multiple times or if a request is sent to execute a file with a specific command. In such circumstances these attempts trigger the corresponding rules and the firewall program blocks the attempts in real time, then records detailed information about them within its logs. ModSecurity is among the most effective software firewalls out there and it can protect your web apps against thousands of threats and vulnerabilities, especially if you don’t update them or their plugins frequently.