Have you ever found yourself sitting in front of your PC with the notorious blue screen? Maybe you have an extra system around the house you want guests that visit your home to use versus them using your personal PC. What if over a long holiday weekend you happen to forget your password after a recent reset? All of these scenarios can be addressed with the use of a live CD. A live CD is a convenient way to run an operating system on a computer without the use of a hard disk drive. There is a vast array of different operating systems that are available as a live disk including, Ubuntu, Back Track, Knoppix, Windows PE, Fedora, Archie, Klax, Clusterix, just to name a few. Most of the live disks you find are some variant of, but not limited to, a Linux/Unix distribution. Depending on the end usage, they have evolved over time to come with a variety of applications for all spectrum of disciplines and areas of interest. Live disks can serve so many other functions, some of the security specific functions include: network sniffing, file integrity checking application, security testing, network discovery, network port and service identification, vulnerability scanning, wireless scanning, password cracking, remote access testing, and penetration testing.
Live CD's are extremely important for from a security perspective because of a number of reasons. First situation may be a primary educational institution or municipal organization where the administration would want to limit certain abilities of the user such as; installation privileges or even write capabilities to the internal hard disk or secondary memory considering there is a designated monitored hard drive available for data saves. Utilizing live CD technology in this situation would alleviate not only virus and malware infections but would also allow the users to have a better performing PC. Another scenario would be a corporate security professional on the job at a Fortune 500 company using live disks to analyze the companies network to mitigate risk and vulnerabilities and the exploitation thereof. Running security tools from live disk distributions like Back Track and Knoppix STD allow a security professional to run different test on various components and hardware on nearly any platform that will enable them to make informed decisions based on the output of the utilities. Lastly, a scenario that may be more pertinent to the everyday PC user; normal household network security. With the changes in technology and computational performance, on what seems to be more of a daily basis rather than the 18 month estimate proposed by Moore and colleagues, users need to be aware and take appropriate actions to potential weaknesses in their own home network by taking advantage of live disk technology. A lack of knowledge of security risks along with frivolous behavior while surfing the web can be to your detriment.
The beauty of live disks is simplicity. Each of the types of media in which they are on (CD, DVD, or USB) are ubiquitous, easily dispensable, and always replaceable. You can take your live disk with you to nearly any machine and run your preferred OS and utilities with no worries of corrupting existing files or applications and with the ease of mind that you are safe from viruses and malicious software that would normally corrupt conventional desktop OS's. To take it a step further, some of the live disk distributions allow the customization of installed utilities and custom scripting capabilities to meet the needs of your specific application.
References:
http://csrc.nist.gov/publications/nistpubs/800-115/SP800-115.pdf
http://www.nu2.nu/pebuilder/
http://www.computerweekly.com/Articles/2006/09/05/218285/protecting-wireless-networks-step-1.htm
http://lifehacker.com/232963/screenshot-tour-how-to-crack-a-windows-password-with-ophcrack-live-cd
ftp://download.intel.com/museum/Moores_Law/Video-Transcripts/Excepts_A_Conversation_with_Gordon_Moore.pdf
Google Group:
http://groups.google.com/group/itec5321fall09/web/Portfolio_Assignment_01_Live_CD.doc?hl=en
