Traditionally, attackers would place a backdoor on a compromised system. If the front door provided authorized access to legitimate users, the backdoor applications allowed attackers to return to an exploited system and have access to services and data.
Unfortunately, the classical backdoors provided limited interactivity and were not designed to be persistent on the compromised systems for extended periods. This was viewed as a significant shortcoming by the attacker community, because once the backdoor was discovered and removed, additional work was required to repeat the compromise steps and exploit the system, which was rendered more difficult by the forewarned system administrators defending the network and its resources.
Kali now focuses on persistent agents that, if properly employed, are more difficult to detect. The first tool we will review is...