If any product is successfully managed with Leak tests, which means that it can protect against attacks based on the specific vehicle theft. At the moment there many techniques that actively exploited by hackers and serious security programs should know and be able to reflect all of them. Cyber-criminals do not stand still, and every day create new sophisticated methods of theft information from users' computers, and for this reason that the creators of software for safety should always be alert and to create new methods to protect their customers. By the time Windows XP in 2001, on the internet there malicious programs such as Trojans and spyware that are freely able to steal sensitive data and transmit this information to unauthorized parties over the network. To prevent similar events company specializing in security, entered the market with solutions of a class 'personal firewall', which were designed to block the action initiated by unfairly applications by blocking their access to Network. To test how effective such security programs, experts and technicians have developed special tools for the simulation of possible attacks – test program tests the ability firewall to control their actions, and warns the user that the computer has detected an attempt to connect to the net. These test tools and got the name 'leak tests', they were relatively simple, but at the same time, they able to identify serious flaws in the protective instruments of those times. The first leak tests used simple methods to check security, such as the substitution of the name of trusted programs and launch trusted programs with modified parameters that gave the command to send a specific text content on a remote resource by using the normal application.