Personal Firewall and Personal Firewall Plus will include outbound blocking and "application fingerprinting" to protect users from Trojan Horse programs and spyware that may have been installed on their computers.
Once the firewall is in place, no application will be able to communicate outside the computer without the user's consent. The first time an application requests access to the Internet, the firewall alerts the user and asks if this is permitted. Each trusted application is "fingerprinted" and allowed Internet access. Other applications are blocked.
Symantec's upgraded Norton Personal Firewall 2002 also claimed to control which applications can access the Internet.
The McAfee Personal Firewall service costs $29.95 (£19.40) annually. Personal Firewall Plus, which includes a graphical trace utility that lets the user trace an IP address on a world map, costs $39.95 (£25.80).