10.3 VMware

VMware enables you to simultaneously run both Windows NT and Linux by creating a “virtual machine” under a host operating system. This enables you to reap the benefits of both operating systems without having to constantly reboot your system. If you run VMware from within the Windows NT system, a window will pop up that shows the virtual machine booting. Everything from memory check to operating system choice is displayed within this window. The same scenario is true if you boot Windows NT from within Linux. The windows can be made full screen for ease of use, and the ctrl-alt-esc key combination allows you to switch the mouse from the virtual machine and the primary operating system. This allows you to switch back and forth between the operating systems in order to use specific tools. This additional functionality is not without its downside. VMware halves available RAM. If you start with 128MB of RAM, by using VMware you will have two operating systems, each with 64MB of RAM. Also, the added strain on your processor will make each operating system run noticeably slower. During the discovery phase of penetration testing, this added value can be worth the strain. However, as you target specific systems, you will find that it is best to generally launch the penetration test from a laptop running the same operating system as the target, and you may not need the dual-operating system capability provided by VMware.

When using VMware, both operating systems appear as a separate computer on the network. In fact, each binds a separate IP address to the network interface card, and a scan from the network shows two separate computers. Keep this in mind when you are configuring many of the tools that require you to input your IP address to receive return traffic. Users often incorrectly use the IP address of the opposite operating system, causing hacks to not work and leading users to spend time figuring out why.

Unfortunately, VMware is not free. At the time of this writing the list price for the product is approximately $299. A student/hobbyist license is available for $99, and you can obtain a free 30-day evaluation license to try the product. You can purchase VMware directly from www.vmware.com.

Installing and configuring VMware is relatively simple. The instructions and documentation are detailed. Essentially you need a system with Windows NT, Linux, or Windows 95 loaded. You install VMware on this partition and then create guest “virtual operating systems” that are directories in the native file system. Fortunately, the configuration wizard guides you through the installation and configuration of each guest operating system. Remember, you need a valid license for any operating system you install. Once you have VMware and your guest operating system(s) configured, you can easily power VMware on and off and switch between operating systems by selecting the operating system you wish to use. You can install software on each operating system just as if it were the native system. You simply use VMware to select the desired operating system and load the software just as you normally would. Software installation utilities embedded as part of the VMware product can assist you in installing a new operating system.