ModSecurity is a highly effective web app layer firewall for Apache web servers. It monitors the entire HTTP traffic to an Internet site without affecting its performance and when it discovers an intrusion attempt, it prevents it. The firewall additionally keeps a more detailed log for the traffic than any web server does, so you will be able to keep track of what is happening with your websites a lot better than if you rely only on standard logs. ModSecurity employs security rules based on which it helps prevent attacks. For example, it detects if somebody is attempting to log in to the administrator area of a specific script a number of times or if a request is sent to execute a file with a particular command. In such instances these attempts set off the corresponding rules and the firewall blocks the attempts in real time, then records comprehensive info about them inside its logs. ModSecurity is amongst the most effective software firewalls out there and it can easily protect your web apps against a large number of threats and vulnerabilities, particularly if you don’t update them or their plugins often.