Since most users do not know which firewall to choose it is becoming important to learn more about advantages and flaws of each product. We have already tested how effective most popular firewalls are in making users’ computers stealth (invisible) on the Internet. Now our goal is to test outbound filtering features provided by today’s firewalls.

Firewalls use outbound filtering features to monitor all outcoming connections and block malicious programs such as trojans, spyware, adware when they try to connect to remote address (that is actually a cracker). Most firewall users are confident of their firewall and do not even suppose that outbound filtering feature of their firewall can be bypassed. As outbound filtering is the major part of firewall protection we can claim most users do not suppose their firewalls are not really protecting them.

Meanwhile several security experts have created so-called Leak tests which question the efficiency of outbound filtering feature used by some personal firewalls. Such tools act like trojans (backdoors) and demonstrate that it is possible to bypass firewall’s protection.

To test outbound filtering features of the leading firewalls we have selected five Leak Test tools. These tools are: LeakTest (by Steve Gibson), YALTA (by Soft4Ever), TooLeaky (by Zensoft), FireHole (by Robin Keir) and OutBound (by HackBusters).

Then we have downloaded eight leading personal firewalls to compare how these products do against the Leak tests. Each firewall was tested with default settings. In other words we have not re-configured the firewalls after they had been installed on the system. The reason to test firewalls with default settings is most users are having difficulties in configuring firewalls so they do not change certain settings after they install the program and instead use default configuration.