This detection rule monitors for potential reverse shell activities on Linux systems by inspecting the execution of background processes that may open a socket in the '/dev/tcp' channel. The rule specifies the conditions under which a process is considered suspicious, focusing on the use of background commands like 'setsid' and 'nohup' in conjunction with specific arguments that indicate socket activity. The intention is to detect adversaries attempting to establish backdoor reverse connections, a common tactic used in cyber intrusions. A risk score of 47 signifies a medium level of concern, warranting investigation into any incidents flagged by this rule. The rule requires integration with Elastic Defend to function effectively, emphasizing the need for correct setup and configuration through the Elastic Agent and Fleet. If triggered, investigators are advised to verify process details, user behavior, and network activity to assess the legitimacy of the processes in question and respond appropriately, including isolating affected hosts and reviewing historical data for further insights into the potential compromise.