This article provides a step-by-step demonstration of a real-life network attack simulation, covering six stages from Initial Access to Data Exfiltration. It emphasizes the importance of testing detection systems, highlighting the need for multiple choke points in defense strategies. The attack flow, based on the MITRE ATT&CK framework and Atomic Red Team, illustrates common techniques used by attackers, such as spear-phishing, tool transfer, discovery, credential dumping, lateral movement, and data exfiltration. It underscores the significance of a defense-in-depth strategy and multiple layers of security to thwart such attacks effectively.