ModSecurity is a powerful web application layer firewall for Apache web servers. It monitors the entire HTTP traffic to a website without affecting its operation and when it discovers an intrusion attempt, it prevents it. The firewall furthermore keeps a more comprehensive log for the site visitors than any server does, so you shall manage to monitor what's going on with your Internet sites a lot better than if you rely simply on standard logs. ModSecurity employs security rules based on which it prevents attacks. For example, it detects whether someone is trying to log in to the administration area of a certain script multiple times or if a request is sent to execute a file with a specific command. In these situations these attempts set off the corresponding rules and the firewall blocks the attempts instantly, after that records detailed information about them within its logs. ModSecurity is among the best software firewalls on the market and it could easily protect your web apps against many threats and vulnerabilities, particularly if you don’t update them or their plugins regularly.