Contributed by Melih Abdulhayoglu:

Comodo research shows that over 50% of desktops have been converted to zombies. They are possessed by unwanted programs that use the host computer to send spam, or steal confidential information.

If you think you are safe, because you are using anti-virus and anti-spyware software, think again. You may already have spyware happily calling your computer home.

A/V and A/S programs are like cops that only look for murderers by using photos. No photo, no way of identifying the murderer.

But how do you handle a new virus or a new spyware that your A/V and A/S software does not know anything about?

That’s what a modern Personal Firewall is useful for, providing you visibility about who is making a call home from your machine. Yes, they also protect you from people trying to hack into your machine, but the real value in this spyware-ridden computer world, is providing you the visibility about your connections. Who is connecting to what, both to and from your machine.

How will you know if the personal firewall is good enough? One way is to run a leak test on your firewall. If your firewall leaks, then it won’t protect against malware that is calling home.

[Editor’s note: Firewall Leak Tester links to external tests that check 19 different types of firewall leaks.]

fyi: Melih Abdulhayoglu is president of Comodo Group. Comodo offers a range of trust and security enabling products, and services, including SSL certificates, password management, anti-virus, anti-spam and secure messaging solutions. Comodo’s free Personal Firewall for Windows 2000 and XP SP2 was recently recognized as a PC Magazine Editor’s Choice.

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