Virtualization for security

Vista of fluffy white clouds



Think about it: create a VM of Windows XP similar to what your users have installed, and then use that image to test new software, policies, and methods. Make a mistake or run into a problem? Either roll back to an earlier version of the VM, or just blow it away and copy over a backed-up copy of the original image. Want to experiment with Linux or any of the cool software tools coming out all of the time, like Zimbra or Asterisk or TWiki? Just create a VM, or download a VM that someone else has already created and start modifying it to suit your interests. How about a honeypot for your network? Rather than sacrifice a machine, use a VM instead. The list goes on and on, and I fully expect that many of you smart readers will list other good uses you already have for VMs in the Comments section below.

Virtualization for ordinary users

It's not just the computer guys who will benefit from the increased usage of virtualization technology, however - it's also the ordinary users. Mike Danseglio, a Microsoft program manager in the company's security group, recently had this to say at a security conference: "When you are dealing with rootkits and some advanced spyware programs, the only solution is to rebuild from scratch. In some cases, there really is no way to recover without nuking the systems from orbit." So it's come to that. Everyone reading this knew it all along, but there it is in black and white - if a Windows machine gets infected, wipe it and start again from a baseline install. Virtualization, however, makes that easy, affordable, and quick.

I've been advocating it for years: put Linux on everyone's computer in your organization. Start with a secure base. I'm talking about a stripped down distro, with little more on it than the kernel, the shell, and whatever X, GTK, or QT libraries your virtualization solution requires. On top of your Linux install, install your virtualization software and then the Windows du jour. Set things up so that on boot, Win4Lin or VMWAre (or whatever else you're using) loads by default and then immediately loads Windows in full-screen mode. Trust me: your users won't even realize that they're not "really" running Windows. To them, they see Windows, they're using Windows, all the software they expect is right there, and everything works just like normal.

Underneath, however, your virtualization software, coupled with the powerful networking ability of Linux, will make your life infinitely easier. If a you receive a phone call that a problem has developed on Bob's "Windows computer" in legal, just use SSH to run a script that closes the virtualization software, blows away or backs up the damaged Windows image so that you can review it, and then copies a master copy of the Windows VM from your server. In just a few minutes Bob will be back up and running, and he'll never know how easy you have it.

To me, this is a no-brainer. It's easier all around, it's more secure, and it's a simple way to get a handle on the horrendously complicated situation most organizations find themselves in as they try to manage a network of vulnerable Windows machines. Give the software and technologies I've mentioned in this article a try, and I think you'll find that they'll become integral tools in your security toolkit. As for me, I'm going to head outside for a little walk. It's a gorgeous day, and I feel like breathing in the air, hearing the world change around me, and looking up into the sky above St. Louis to look for some elephants.

Scott Granneman is a senior consultant for Bryan Consulting Inc. in St. Louis. He specializes in Internet Services and developing Web applications for corporate, educational, and institutional clients.

This article originally appeared on SecurityFocus

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