Today’s firewalls not only provide protection from external attacks
but also control over outgoing traffic, because often the Trojan
programs that penetrate a computer are capable of gaining remote control
over it, scanning for confidential information and tracking user
activity. Trojans of this type then use a number of methods to pass the
information on to their “owner”. Some malware is also capable of
transmitting itself from an infected computer to another machine;
control over outgoing traffic can prevent any further spread.
Leak tests, set up with the help of special programs that simulate
the activity of Trojans bypassing protective measures, are used to check
personal firewalls for internal leaks.
One of the biggest leak tests was carried out by the team from the
matousec.com project. The checks involved each firewall undergoing 77
tests for leakage. For each test a product passed successfully using its
default settings it got a score of 125; if a configuration setting of
maximum security was required to pass the tests, the product got a score
of 100 for the test. The tests had a maximum combined score of 9625
(77*125). The diagram shows the final scores of the products tested. The
Kaspersky Lab product got 8475, which according to the matousec.com
scale is “Very Good”.