Wall off the WorldInstall a Better Firewall in an Afternoon

More advanced firewalls can be time-consuming to install, but they are not difficult to use. Take the time to fortify your defenses. It is really worthwhile.

Install a Two-way Software Firewall

Installing a third-party firewall gives you two-way protection. It stops hackers and worms from coming into your computer from the Internet. And if your computer becomes infected, it stops worms, spyware, and viruses from communicating out to the Internet.


If you already have Norton Firewall or McAfee Firewall, these programs are as good as the pro versions of the free firewalls recommended in this chapter.

I recommend two free third-party firewalls: SyGate from www.sygate.com and ZoneAlarm from www.zonealarm.com.

Here's how to install the free version of ZoneAlarm, my favorite:

  1. Use Internet Explorer or Firefox to visit www.zonealarm.com.

  2. Choose Home/Office Products from the left menu (see Figure 3.8) and then choose ZoneAlarm from the list of products.

    Figure 3.8. ZoneLabs makes a free version of ZoneAlarm available for personal use and to charities.
  3. On the ZoneAlarm page click the Free Download button and choose the link that says Download Free ZoneAlarm.

  4. You are presented with a pop-up window (if you are using Internet Explorer) that says Run or Save. Choose Run.

  5. You might get a security warning box. Click Run. The program begins to install (see Figure 3.9).

    Figure 3.9. When ZoneAlarm downloads you might get a security warning. It's OK to click Run and let the download proceed.

  6. Choose a folder to install ZoneAlarm in. The suggested folder is fine (see Figure 3.10). Click Next .

    Figure 3.10. The first thing you see when ZoneAlarm starts to install is the option to change the folder where it will install. The default folder is fine.

  7. Type in your name , company (optional), and email address. In Chapter 5, "Spam: Unwanted Email from Hell," which is about spam, I always recommend you use a secondary email address for things like this. I'll leave the decision up to you.

  8. ZoneLabs promises not to misuse your email address (but I trust no one). Choose not to receive news and updates (and an excuse to market to you), but do choose to register so you can download updates.

  9. Choose Next and read the license agreement. Note that it offers the free version to individuals for personal use and not for profit charities. Accept the terms by checking the box and click Install.

  10. The program installs itself and before starting it asks you some optional survey questions. Afterwards, choose to start ZoneAlarm by clicking Yes on the box that pops up.

    Steve Gibson, of GRC.com, coined the term spyware when a program on his computer started to communicate out to the Internet as he was testing an early version of ZoneAlarm.

  11. If your Windows Firewall is turned on, you are asked if Windows Firewall should keep blocking ZoneAlarm (see Figure 3.11). Ironic, don't you think? Choose unblock. After ZoneAlarm is installed, be sure Windows Firewall is off.

    Figure 3.11. Windows Firewall tries to block the ZoneAlarm installation. Click Unblock to let it proceed.

  12. Next the install asks if you want to use the free version of ZoneAlarm or the 15-day trial version of ZoneAlarm Pro. Choose ZoneAlarm unless you think the extra features are worthwhile. Personally, I think the pro version is great if you're willing to pay for it. But for these purposes, choose Select ZoneAlarm and click Next, and then click Finish to configure the program.

  13. At the Welcome screen, click Next and choose Yes (Recommended) to configure ZoneAlarm with your Internet connection. Click Next and then Done.

  14. You are asked to reboot your computer, so close all your running programs and click the OK button to restart.

  15. When the system reboots, ZoneAlarm runs and you see a little icon in your System Tray (bottom right) that shows whether it is dormant or active (see Figure 3.12). When it's dormant , it shows as a red Z and yellow A. When data is flowing in and out of the computer, it changes to look like a moving audio meter.

    Figure 3.12. ZoneAlarm shows up as an item in the Windows System Tray in the bottom-right corner of the screen.
  16. When a program tries to access the Internet from your computer you see a pop-up alarm (see Figure 3.13). If this program is known to you, choose Yes and choose Remember This Setting so you're not bugged again next time you run that program. It is normal for some programs to use the Internet to check for updates ( especially antivirus programs and anti-spyware software), but you'll be surprised how many programs will try to communicate with the Internet.

    Figure 3.13. ZoneAlarm asks you for input when a program on your computer that is not recognized tries to access the Internet.
  17. Of course, if something weird tries to communicate with the Internet and ZoneAlarm alerts you, choose No and block it. ZoneAlarm should give you a sense of what it is, so record that information and then do either a virus and/or spyware scan or research the program on the Internet to try to figure out what it is. It might be a background Windows process and could be legitimate , but it's worth finding out.

  18. You'll have to suffer these for a few days until all the programs that access the Internet are caught by ZoneAlarm and approved by you. Then you shouldn't be bugged much after that until you install new programs or there's a legitimate infection that is caught by the firewall. You'll also start receiving security alerts if you change ZoneAlarm's security settings. For instance, if you change the security level from medium to high, ZoneAlarm starts pestering you again about programs accessing the Internet. It's annoying, but a necessary evil.

  19. You might see inbound attacks, too. Most of these could be hackers scanning for opportunities or worms trying to access your computer. Because you've seen the alert, you are protected (see Figure 3.14) and don't need to take any further action. There is an option for more info , however, if you are interested.

    Figure 3.14. Incoming attempts to access your computer are shown in a pop-up alert by ZoneAlarm. This inbound contact is coming from a computer on the same home network.

  20. If the alerts become too annoying, turn them off by opening ZoneAlarm, clicking Alerts & Logs (on the left side), and choosing Off (see Figure 3.15), although I think the button should say Shut Up, You Are Driving Me Crazy.

    Figure 3.15. Thankfully, you can turn the inbound alerts off in ZoneAlarm because they will eventually drive you bonkers.

Double your Defense with A Double Firewall

If you have a home network router, your computer and other computers on the network (such as your spouse's laptop and your children's computer) are protected from the outside world.

However, you are not protected from the computers inside the router. So you might want to leave on the Windows Firewall or a two-way firewall such as ZoneAlarm on your computer. Here's why:

  • Maybe your children or roommates have their own computers and they regularly infect it with spyware or viruses.

  • A friend or family member sometimes comes over with an infected laptop and connects it to your home network.

  • You leave your wireless network unsecured and a wireless network snoop connects and exposes your computers on the network to viruses, spyware, or their own curiosity (Learn more about wireless network snoops in Chapter 6, "Wireless Network Snoops : Lock Down Your Wi-Fi Network," on p. 151 .)

Install a Hardware Firewall

For sheer firewall simplicity, I recommend installing a home network router with built-in network address translation (NAT) firewall capabilities (discussed earlier in this chapter on p. 95 .

Some things to keep in mind when it comes to a NAT firewall are

  • It does not use any memory on your computer, so the firewall is invisible.

  • It works silently to defend your network. You'll never see pop-ups, alerts, or other annoyances.

  • It stops inbound threats but won't stop outbound nasties that might be on your computer.


If you would like to check your firewall's defenses, check out Steve Gibson's free firewall test called ShieldsUP! It's an excellent and well-documented online test available at www.grc.com that runs tests against your computer or home network and explains in careful detail where you are vulnerable.

To take advantage of a NAT firewall, you need to buy an Internet-sharing device called a home network router from any one of several well-known vendors , including

  • D-Link www.dlink.com

  • Netgear www.netgear.com

  • Linksys www.linksys.com

  • Belkin www.belkin.com

  • SMC www.smc.com

  • Apple www.apple.com

These routers will cost you about $60 or less (unless you choose Apple's Airport Extreme and then you're in for $200). A router connects to your high-speed Internet modem from either your cable TV or telephone company and shares that connection with several computers in your home. Your computer(s) in turn connect to the router via network cables or using a wireless connection (also known as Wi-Fi).


If you choose a wireless connection, most new laptops have built-in capabilities for this. You can, however, buy wireless adapter cards for both a PC and laptop without built-in wireless.

The router configuration is fairly straightforward. When you set the device up, there is a walk-through wizard that configures your computers and the router so they work together. Both Macs and PCs can co-exist on a router together and even share files with each other.

When you install the network, you need settings from your Internet provider to input into the router during setup. Be sure to check Chapter 6, starting on p. 151 , to learn about wireless network snoops and how to configure your router to be secure. After the router is set up and running and you can connect to the Internet with your computer(s), there's nothing further to do. That NAT firewall runs automatically.


If the idea of setting up a router scares the ham out of your sandwich, you should check out Mark Edward Soper's excellent book called Absolute Beginner's Guide to Home Networking .

The Absolute Minimum

  • Among geeks , the word hacker has many definitions, including a good programmer, a bad programmer, or a person that modifies technology hardware. In the mass media, it's a person that accesses a computer they don't own without permission.

  • A cracker is what computer break-in artists called themselves , but we call them hackers.

  • Crackers' motivations are varied. They hack to steal, to protest, to make money, to terrorize to prove a point, oras George Mallory said about Mount Everest and a very nice donut earlier that day"because it's there."

  • Personal computers are usually hacked so they can be turned into zombies and be remote controlled to attack other computers, used as a storage for illicit information, or used to send spam. Sometimes they are hacked by identity thieves who steal personal financial information.

  • Windows XP has a built-in firewall. When installed, Service Pack 2 turns it on for you.

  • A third-party firewall is a program that acts as an electronic wall on a computer to stop inbound traffic and, usually, outbound communication that contain viruses, spyware, and other malicious programs.

  • A hardware firewall is a device that blocks inbound traffic from the Internet. Network address translation technology in a home router provides a firewall function.

  • It's hard to tell if you have been hacked. The only way to have complete peace of mind after you have been hacked is to wipe your computer clean and start fresh.

  • You should ensure you have at least one firewalleither hardware or softwareturned on, protecting your computer from viruses and worms.

Absolute Beginners Guide To. Security, Spam, Spyware & Viruses
Absolute Beginners Guide to Security, Spam, Spyware & Viruses
ISBN: 0789734591
EAN: 2147483647
Year: 2005
Pages: 168

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