ZoneAlarm is a software firewall that can help to protect your computer from malicious Internet attacks. The software is easy to configure and has always been very stable and reliable on my Windows XP systems. Once you have Zone Alarm installed, it will alert you if a program is attempting to access the Internet by displaying a pop-up window (see Screenshot 1). If you want the program to connect, you can give it permission via the "Yes" or "No" buttons on the Zone Alarm pop-up. Of course, there are some programs, such as your browser and email client, that regularly need to access the Internet so having to give permission for these programs every time they need to connect would be inefficient and annoying. However, ZoneAlarm allows you to permanently give or withdrawn permission for a program to connect by checking the appropriate box. If you click "No" on the Zone Alarm pop-up, the program is blocked from connecting to the Internet. Thus, if you have a Trojan or spyware component that tries to "phone home" you can stop it before it makes the connection.
However, the above is only half of the story. ZoneAlarm also blocks incoming connections. Thus, if a malicious attacker tries to gain access to your computer, the connection will be blocked. You can choose to receive pop-up alerts regarding these incoming probes (see Screenshot 2) or you can simply have ZoneAlarm silently do the blocking in the background. Many incoming probes are random port scans or non-malicious probes from your ISP, so I usually choose to turn off the incoming alerts, as they can become annoying.
ZoneAlarm activates at Windows start-up so that it is continually protecting your system. A dynamic icon that resides in the system tray provides quick access to the ZoneAlarm user interface and graphically displays Internet activity. Right-clicking the icon allows you to quickly stop all Internet activity should the need arise. The right-click menu also allows you to temporarily disable the firewall.
Find out more about ZoneAlarm via the link below:
Screenshot 1 (Outgoing access alert):
Screenshot 2 (Incoming access alert):
Screenshot 3 (User Interface):
Write-up by Brett M. Christensen