The 'Simple HTTP Web Server Connection' rule is designed to detect connections accepted by simple HTTP web servers implemented using Python and PHP. These servers are often exploited by attackers to retain access to compromised systems, enabling them to upload reverse shells or other malicious payloads. The rule leverages an EQL query to monitor for events where a process that matches specific criteria (e.g., running as a PHP or Python web server) rejects connections. The alert mechanism incorporates risk scoring and is configured to gather data from Elastic Defend for effective threat detection. An investigation guide accompanies the rule, highlighting potential investigation and response steps to manage alerts effectively, awareness of false positives due to legitimate development activities, and incident response recommendations to mitigate risks associated with unauthorized server activity.