In Linux/Unix like operating systems everything is logged. Many valuable log files are automatically created for you by Linux. You can find them in your /var/log directory. This folder contains logs related to different services and applications. In this folder apart from other logs files we have some files such as utmp , wtmp and btmp . These files contains all the details about login’s and logout’s which are from local as well as from remote systems and system status such as uptime etc.
Many technologies are leveraged to achieve business objectives and values to customer, but it comes with a price of security risk associated with them. Managing those risk would be an superficial act wasting time and money unless we understand how they are configured, maintained and operated, and then understanding the terms, definitions and concept associated with those technologies becomes paramount, Then you know how to control these risk effectively and efficiently