Use the HOSTS File to Assist Privacy

March 8, 2008 – 4:03 PM

Everyone likes to be a good host, but bad guests get carried away. They?ll stay too late or empty bottles too soon. They could even break something along the way. That?s why you take precautions as a host.

Think of your Windows HOSTS file in the same way. By properly setting up your HOSTS file, you can save yourself grief from bad Internet visitors. This is done by circumventing the source of pop-up ads and banners.

Keep this in mind: A proper HOSTS file is just one of many defenses needed to thwart unwanted Web visitors. You still need virus protection, ad blockers and spy scans to bar the bad stuff. You also need them to detect any currently lurking on your computer.

The Preliminaries
The HOSTS file resides in your Windows folder, or a subfolder, depending on your Windows version. The domain names and Internet Protocol (IP) addresses of other computers can be listed there. So, the HOSTS file can act as an address book when your computer wants to call another machine.

The Problem
Advertisers use your surfing habits to target products that match your interests. That’s why pop-up ads, banners, adware and spyware have become so invasive.

The HOSTS file works like this. When you type a Web site into your browser–say,–your browser first checks the HOSTS file for the IP number. If the HOSTS file contains this address, your computer stops looking and ?calls? the number. If not, your computer goes to the Internet and finds the IP number there.

Spyware works the same way. So you can use the HOSTS file to trick the spyware.

The Patch
This is actually pretty simple. Redirect the connection back to your own computer. To do that, put the spyware entry in the HOSTS file. The entry looks like this:

So let’s say that spyware on your computer is trying to contact the Bad News Advertising Co. It tries to go to Your computer first goes to the HOSTS file, looking for the IP number. Sure enough, it is there. But the number ( is your computer, not the address of the Bad News Advertising Co. Because it is your computer, the request simply dies. The spyware is marooned inside your computer.

Windows comes with a HOSTS file, but there is only one line in it: localhost

Localhost is your computer. To make the HOSTS file a worthwhile spyware fighter, you would have to enter hundreds of evil domain names, such as, along with your IP number ( Fortunately, there?s another way. Custom HOSTS files are available on the Web. You can get a good one at:

Can the spyware people get around this? There are ways. But so far, at least, they haven?t bothered. If you install a HOSTS file, along with programs to block and eradicate spyware, you?ll be much more secure. You can find programs to block and eradicate spyware on my site at:

Stick with me. We can defeat these people.

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