Walt Mossberg

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Personal Technology

GreenBorder Traps Computer Bad Guys Inside a Virtual Fence

One reason the Web browser is a dangerous conduit for malicious software, like viruses and spyware, is that it can access all the features of your computer while simultaneously connecting you to other computers around the world whose safety can’t be assured.

The result is that criminals can use the browser as a gateway to plant all kinds of bad software on your PC and to steal your personal information by accessing your files or recording what you type.

Today’s common defenses are hit or miss. You can install antivirus and antispyware software, but those must be updated constantly to recognize new attack patterns, and sometimes the bad guys get ahead of the defenders.

Now, a small Silicon Valley company called GreenBorder is trying a radical approach. It has developed a product that isolates the browser from the rest of the computer, without impairing your Web browsing. It erects a sort of fence around the browser. Inside that fence, the browser runs normally, along with associated programs like media players. But the browser can’t be used to install bad software or to spy on the rest of the computer outside the fence.

With this product, called GreenBorder Pro, any malicious software you pick up is trapped in a computing environment — called a virtual session — that exists only inside the fence and can’t affect any key files or settings outside.

Once you quit the browser, this virtual session simply disappears, along with any bad stuff that has collected within it. Your files and settings remain unaffected. You can even purge the bad stuff from the virtual environment at any time by clicking on a command called Clean and Reset GreenBorder.

For instance, inside a GreenBorder Pro session, you might get infected with a “browser hijacker,” a spyware program that permanently changes your browser’s home page and search page to sites operated by sleazy companies. But once you quit the browser, or click on Clean and Reset, the hijacking effects disappear.

To show it’s protecting you, GreenBorder Pro places a literal green border around the browser. It also displays a summary of the malicious software it trapped inside its border and prevented from affecting your files and settings. If you deliberately choose to download a file, it gets placed in a special folder on your PC and marked with its own green border. It then runs in a protected session, just like the browser.

One big advantage of the GreenBorder Pro approach is that there’s no need to try to stay ahead of the bad guys’ techniques. GreenBorder doesn’t have to collect and update signatures of known bad programs.

GreenBorder Pro, available for download at greenborder.com, works only with Microsoft’s Internet Explorer browser for Windows, the most popular but least secure major Web browser. GreenBorder costs $50 a year, but is free for one year to the first 10,000 to download it.

I tested GreenBorder Pro on three different Windows computers, and found it easy to use. While it is difficult to test a negative, I deliberately used GreenBorder Pro to access numerous known bad Web sites, those that typically install unwanted adware and spyware on a PC.

Before starting, I ran both an antivirus and an antispyware scan to ensure each test machine was clean. I ran the scans again after quitting GreenBorder Pro, and the PCs were still clean, despite all those visits to bad sites. GreenBorder Pro reported that it had blocked dozens of attempted “file changes” and hundreds of attempted changes to the Windows Registry, the part of Windows that stores instructions for running software.

GreenBorder Pro has two other major features besides its basic function. One, called Privacy Zone, sets up a special browser mode for those times when you are visiting a Web site where you expect to be entering passwords or credit-card numbers. In this mode, the Clean and Reset process is performed automatically first, to purge any spy software that may be operating, and all traces of your Web activity are wiped out when you’re done. A yellow border is placed around the browser when you are in the Privacy Zone.

The second function is called SafeFiles. It lets you erect a fence around files from sources other than your browser, including email attachments and files you copied onto your PC. This is an extra-cost option priced at $14.95 a year.

There are some limitations to GreenBorder Pro. It won’t clean out existing viruses and spyware on your computer, or automatically block invasions that aren’t from Internet Explorer. You still need standard security software. It also won’t prevent you from being tricked into giving up private data. Also, some legitimate software downloads and installations will fail with GreenBorder Pro. You’ll have to run a browser in normal mode to get the downloads.

Also, I don’t see why you should pay $50 every year, instead of just once, for software that boasts that it doesn’t require updates. (The company says the annual payment covers better support and new features.)

But GreenBorder Pro is a novel and very promising weapon against malicious software.