Footprinting and Reconnaissance - Determining the Operating System

Determining the Operating System on which the server runs is the most important part of Hacking. Mostly, hacking is breaking-into the target's system to steal data or any such purpose. Hence, the security of the system becomes thing of prime importance.

Why is determining the Operating System so important?

A few important things depends on the type of operating system of the server. These are :

• Programs that can be installed on the server : Suppose you want to install malware like keyloggers or other spying software on the target's system, then you must know the type of OS he/she is using. Its because, there comes different software for different OSes. Like you can't run IOS apps on Android and vice versa. Also, you can't run windows EXEs on Linux.
• Commands that can be executed : This is important in the case when you want to remotely control a system. Suppose that we found a vulnerability in the system and installed a malware in it which allows us to remotely control the server via its Shell. Here, we need to know the shell codes (CMD in windows and BaseShell in Linux). Also, knowing only the shell codes is not enough. It is useless until you know the system on which you have to execute the scripts.
• The storage location of the information about users and passwords : When you want to steal username and password information of users or admin from the server, this is important. It is because, Windows and Linux like Operating Systems have a predefined file (located at a specific path) which stores the sensitive information. So, when you come to know the OS, you just have to move to that path to steal the data information.
• Vulnerabilities for a given operating system : Some of the Operating Systems possess vulnerabilities that can be exploited by attackers. Linux operating system provides the highest security than windows. When you have knowledge about the vulnerability inside an OS, you can target any server running on that OS, exploiting that vulnerability. Recently, windows 10 was attacked by a Zero Day attack and the vulnerability still exists.

Not only determining the OS but also determining the version of operating system is of great use. We know that new versions are released as a patch to bugs in the old versions. Suppose, the target luckily runs on the old version..!! Here, it becomes easy to hack into the system as we are aware to the bugs in the old versions.

Each operating system has a unique set of features and the hacker must know them..

Steps for how to determine the Operating System of a server will be mentioned in my Next Article.