The Internet is a scary place. Criminal malware lurks on legitimate and illegitimate Web sites alike, looking to steal your money one way or the other. Vendors have been scratching their collective heads attempting to make more consumers safer, more often. One of the results has been a class of anti-malware software that I call sandbox protection products. These items encapsulate Internet browsers (and e-mail programs and sometimes any other program you can run) within a virtual, emulated cocoon designed to keep malware from reaching and modifying the underlying host computer.

It used to be that you had to boot with an infected floppy diskette, run an infected executable, or double-click on an e-mail attachment to get exploited. Nowadays, all you have do is surf your browser across the wrong Web page, or the right Web page at the wrong time. Client-side, polymorphic, Internet browser-based exploits account for the large majority of malware infections. And although nearly ubiquitous in use, conventional anti-virus, anti-spam, and host-based firewalls are being challenged as never before to provide protection. In the virtual world, malware can be controlled, limited, and defanged. If the vendor does its job perfectly, everything legitimate the end-user wants to keep is kept permanently, and all traces of malware are erased as if the exploit never occurred.

As this review will show, none of the current solutions are perfect, but they do have value as an additional line of defense. I tested five products: Check Point Software's ZoneAlarm ForceField, Sandboxie, Prevx, Authentium's SafeCentral, and Softsphere Technologies' DefenseWall HIPS. Trusteer declined our invitation to participate, and one of the original pioneers in this field, GreenBorder Technologies, has been purchased by Google and is unavailable for review. I intentionally wanted to cover products that would be new to most of our readers and that have not been reviewed multiple times in the past.

Each product was tested by subjecting it (and the underlying host running Microsoft Windows XP Professional SP2, Internet Explorer 6, Firefox 1.0, and several older versions of browser add-on software) to hundreds of malicious Web links. Unpatched application software was intentionally used to test the defensive capabilities of the reviewed products. I didn't want the latest vendor patches stopping the malware. I wanted the sandbox products to do all the hard work.

I surfed to real-world Web sites that hosted computer viruses, worms, bots, Trojans, malicious scripts, and rogue batch files, then attacked using local and remote buffer overflows, all while logged on using the built-in Administrator account. I used malicious links provided by public and private anti-malware discussion lists and sources. I ran both old and new exploits, attempting to mimic the common threats the average user could encounter while surfing the Internet.

I was keen to see how well programs prevented silent "drive-by" downloads and how well they protected the user even if the user intentionally installed them (as if provoked by social engineering). Some sandbox products only provide protection from silent downloads, which can be furnished by a fully patched system without additional software in most cases. Others provide protection no matter what the user does, which is even more important in today's world of sophisticated social engineering.