The Azure Virtual Network Deleted detection rule is designed to identify instances where an Azure Virtual Network (VNet) is deleted. Such an event can have severe implications, including disabling portal access and disconnecting all resources linked to the VNet, which is critical for maintaining service continuity. This rule raises a high-severity alert upon detection of VNet deletion, as it may signify malicious actions such as ransomware activities, sabotage, or unintended infrastructure removal. The detection mechanism uses Azure Monitor activities to track deletion operations and correlates them with prior events involving the same network resources to understand the impact of the deletion. Additionally, the rule includes steps for investigators to verify the legitimacy of the deletion by analyzing associated resource activities and comparing caller IP addresses against known safe IP ranges, potentially revealing unauthorized access or anomaly patterns.