Have you ever wondered about installing an Operating System (OS) on a CD disc or a pen-drive rather than installing it on a hard drive? If this happens we can use many operating systems on the same machine without compromising much on the Hard-Drive storage space. It would be up to users which OS(s) they wish to use and also when to use. Well, it seems fascinating and if I say “Yes, it is possible” then OMG! it’s so cool. But let me warn you, it has some disadvantages too which I’ll tell about later in this article.
What are they?
Live Discs are completely bootable and a pre-installed fully-operational Operating System in an external CD or a Pendrive (Well it can also be a DVD or sd cards or any other external storage media) that runs on our system and does not need to be installed before using the basic features of Operating System.They do not make any changes to system configuration and also can run without any secondary storage (but they do need RAM ). In order to use live OS in a virtual environment such as using it in VirtualBox, live OS comes as bootable iso files and they are termed as live iso(s).
Why are they useful?
Live Discs are very commonly used by the hackers be it be their beginner level or at an advanced level exploitation tool. It is one of the important things used very frequently by them. Apart from this, they are very useful in many other ways also.
To a hacker, live CD can be used to access files those which are not accessible without administrative privileges. It can be used to exploit user data. Hidden files can be browsed with them. Data and be recovered and restored and also one can bypass Windows permissions. In fact malwares like viruses, worms, spywares, keloggers, etc. can be planted or the system can be infected very easily but it does require physical access to the system.
It can be used to hack Windows Password, damage, corrupt or alter OS files.
Also, many live discs come with a number of utilities for broad field operations which range from making changes to disc partitions to hack a wifi password.
Well, it can also be used the other way round i.e. to recover OS files to backup data. In short, they can also make a dead computer working.
They are also used for the trial of Operating Systems. It provides with the look and feel of it. Almost all distro available today have their live versions available on the net. It is useful in the sense when anyone is new to some OS, he may use live CD for a good start and also he would be clear whether that OS is up to his need or not. In the case of hacking, beginners generally try the live version of “KALI LINUX” during their initial days so as to comfort them with all new console interface and totally different GUI(Graphical User Interface). It provides a great start as compared to when they totally shift to KALI without prior experience of using it. And as a result, they may end up with frustration. Also, a direct transition from Windows to Linux is sometimes harder in the beginning but as the time passes, it becomes easy.
It also helps to check the working of different hardware and to check the support of many accessories.
They can also be used to work anonymously on a system and many people generally prefer live OS for their temporary tasks as they can work on their required OS with required utilities without actually installing the whole OS.
There are many live CD’s available these days and the good thing about them is that most of them are Open Source so you need not purchase them. Here’s a list of live CD’s available so far with their field of use and their release dates:
Drawbacks of using them!
- They are very good for temporary tasks and all the data if not stored somewhere in secondary storage (not RAM), is lost after turning off the live OS.
- For the hacking purpose, they need to have physical access to the target machine but that is not always possible.
- As CD’s are generally read-only device so OS updates are required each time you use it as they are just temporarily stored, or you need to change the Disc very frequently.
- The boot time and the computer response time is generally slow as the reading and writing speed of CD/DVD’s are quite less s compared to Hard Drive but it’ll work fine in case of a USB but it works best in the Hard Drive only.
- All features are not available in the live versions.
- New applications cannot be permanently installed in the live CD/DVD.
- Less RAM storage is available as some of these use RAM as temporary file storage.
If you haven’t used any live CD before, I recommend you to have at least one that can be used in emergency cases. I’ll suggest having at least one of SystemRescueCD, Knoppix, or Hiren’s Boot CD. They’ll prove to be very useful when you need.
Feel free to comment for any queries