Knock Knock. Who's There?

It's the boogieman! Yes, your favorite childhood creepy 'ole boogieman is at it again. But rather than scare you in person, the boogieman is in your computer now...

Now how do you keep him out? Wouldn't it be nice to have your own personal doorman to monitor who to let into your home, and who to bounce?

Like the big burly guy who acts as a gatekeeper to your favorite hangout, you can have your very own personal doorman for your computer. Actually, it's not so much a can, as it is a must - having a personal doorman that acts as your computer's bouncer to the nasties that are out there is not an option, it's an absolute requirement.

Computer networks and the internet weren't designed with security in mind. The "net" was originally designed to allow you to share information with many people and with as little hassle as possible. Unfortunately, that ease of sharing information brings with it one of the many risks you face whenever you are connected to the internet - the risk of sharing your confidential and private information with all the criminals and scumbags out there.

To oversimplify things, your computer is like a house with 65,000 ports or access "doors" to the outside. To make it more scary, every one of these doors is unlocked and open to the world for anyone, or program to use.

Yiikes! That's like living in a glass house in grand central station. No privacy, no security. Back in the early days of computing, everyone made programs to do all kinds of things and programmers played fast and loose with no proper structure. Microsoft is not completely to blame either, since they're trying not to alienate users of older versions of software. But that doesn't absolve them of blame either.

So why don't I just close and lock every door on my computer? You could, but how would your computer talk to the world? How would you be able to access the internet? What you need is a personal doorman at every door to monitor who can come in and who can leave. That's where a "Firewall" comes in.

What's a Firewall?

A firewall is a either a piece of hardware (a box) that you connect to your computer, or more commonly, a software program that you install on your computer. The Firewall acts as a barrier or "wall" that surrounds and protects your computer from the outside world. It's the bouncer that watches every single one of your computer doors for you automatically. No one comes in or leaves without you knowing.

You should NEVER, EVER connect your computer to the internet without a firewall. Never go anywhere unprotected. It takes literally only minutes before a worm, virus or malicious program comes 'a knocking on your computer. There are thousands of nasties out there just waiting and searching for unprotected computers. As soon as they find an open door - they're in. It's as easy as 1,2,3.

Once a worm or nasty virus finds your computer's open door, they'll load anything from more worms, viruses, trojans or keyloggers on your computer and use your computer to do damage to other computers.

A "trojan" is a program that enters your computer either through an open door in your computer, or through email attachments disguised as a picture or screensaver. Once clicked on, the trojan installs it's secret payload onto your computer and starts to damage your computer and wipe out your files. It can also use your computer as a "zombie" to launch attacks against other computers on the internet.

A "zombie" computer is a computer that has been compromised and is under the secret remote control of some scumbag located someplace else.

Keylogger programs. If the virus or worm has loaded a "keylogger" program on your computer, EVERY keystroke that you type, combined with screenshots of your computer screen will be recorded and silently sent to a scumbag's computer. That means all of your personal information will be sent to the criminals lurking out there. Unless you enjoy having your identity stolen, be wary of "free" programs, phishing emails and email attachments.

Did I mention that you should never, ever click on a link or attachment in an email? Well, I'm gonna say it again - DON'T click on attachments or links in emails. Right click and save attachments to a folder on your harddrive, then use a virus scanning program to scan it first.

Again, research programs on techie websites like PCWorld, CNET, and PCMagazine. Then install a firewall. For most people, you can use the free personal version of a program called ZoneAlarm. It's very highly rated, relatively easy to use, and FREE. I know I mentioned earlier to be cautious of "free" programs, but in this case, you can be confident that this excellent free firewall program is legitimate. Power users may wish to purchase the Pro version.

But I have the Windows XP firewall, I don't need another one you say.

Well, you don't need another one if you only want to do half a job. You see, the firewall that comes with Windows XP (the SP2 version) only works as a doorman for programs trying to get IN to your computer. But it does nothing if a program has sneaked in, either via an email or if you accidentally visit a malicious website. While it's watching the front door, creepy nasty programs are stealing your valuables and walking out the back door, 'cause no one's watching what's going OUT of your computer.

So the firewall built into Windows XP is the absolute bare minimum (and that's a really bare minimum) that you should have.

Do a free computer Security Check at GRC.com.

What you really want, is to have your computer appear to be invisible to the outside world. A firewall helps to hide your computer. You should visit a great website called GRC to check if your computer is visible to the world, and to see if all of your computer "doors" are shut and locked. A guy named Steve Gibson runs this website.

There is a free test he offers called "Shield's UP". Click on the link for ShieldsUP and run the tests that "knock" on all your computer doors. Hopefully you'll find that your computer is "invisible" to the world.

A firewall is only one tool in your arsenal against the scumbags that prey on innocent people like you and me. You are always at risk against all the nasties out there unless you have several tools in your belt. You've got to make sure that you also have an Anti-Spyware, Anti-Virus, and an Anti-Foolishness program loaded on your computer.

OK, I made up the last one, but there really is something like an anti-foolish tool - it's called using your head. Common sense if free, buy only if you use it. Be aware and be safe :)