The detection rule titled 'Linux Stdout Redirection To Dev Null File' focuses on identifying command-line activities in Linux systems that involve redirecting standard output (stdout) or standard error (stderr) to the /dev/null file. This behavior is monitored using Endpoint Detection and Response (EDR) agents, utilizing data extracted from process execution logs. The rule is particularly significant due to its association with potential malicious activities, especially those reminiscent of the CyclopsBlink malware, which employs such techniques to obscure changes made to the iptables firewall settings. By redirecting outputs to /dev/null, attackers can hide their malicious commands, making detection harder. If this behavior is confirmed as malicious, it can lead to unauthorized modifications in system configurations, potentially granting attackers ongoing control over the targeted machine. In summary, this rule aims to uncover stealthy threat actions that indicate underlying attempts to manipulate critical system settings without alerting security measures.