ModSecurity is a potent web application layer firewall for Apache web servers. It monitors the whole HTTP traffic to an Internet site without affecting its functionality and when it detects an intrusion attempt, it blocks it. The firewall also keeps a more thorough log for the site visitors than any server does, so you shall manage to monitor what is happening with your sites much better than if you rely only on standard logs. ModSecurity works with security rules based on which it prevents attacks. For example, it detects if somebody is trying to log in to the administration area of a certain script several times or if a request is sent to execute a file with a specific command. In such situations these attempts set off the corresponding rules and the firewall software blocks the attempts in real time, after that records detailed information about them in its logs. ModSecurity is among the best software firewalls on the market and it could easily protect your web applications against a large number of threats and vulnerabilities, particularly if you don’t update them or their plugins often.