ModSecurity is a highly effective web app layer firewall for Apache web servers. It monitors the entire HTTP traffic to a site without affecting its operation and in case it identifies an intrusion attempt, it blocks it. The firewall additionally maintains a more thorough log for the traffic than any web server does, so you will be able to keep track of what's going on with your Internet sites much 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 administration area of a specific script multiple times or if a request is sent to execute a file with a particular command. In such circumstances these attempts trigger the corresponding rules and the software blocks the attempts instantly, after that records detailed info about them in its logs. ModSecurity is among the most effective software firewalls out there and it could easily protect your web apps against thousands of threats and vulnerabilities, especially if you don’t update them or their plugins frequently.