This rule detects modifications to system firewall configurations on Linux systems using the audit framework (auditd). The rule is designed to identify operations where firewall rules are removed or disabled through common utilities such as iptables, firewall-cmd, or ufw. By focusing on commands that either drop connections or remove rules, this detection aims to uncover attempts by adversaries to bypass network security controls that enforce strict access policies. It highlights the importance of monitoring not just the disabling of firewalls but also the specific deletion of individual rules which might allow unauthorized network access. The rule has a medium risk level due to the potential for legitimate administrative actions to trigger it, thereby requiring careful consideration in the context of normal operational behavior. Key references include research into advanced threats targeting firewall configurations.