You have an Azure subscription that contains the resources shown in the following table.

Microsoft Defender for Cloud can provide security coverage for all four resources in this scenario. VM1 can be protected through Microsoft Defender for Servers, which provides workload protection for supported Windows and Linux virtual machines. storage1 can use Microsoft Defender for Storage for threat detection and capabilities such as malware scanning. Vault1 can be protected through Microsoft Defender for Key Vault, which detects suspicious and anomalous operations involving keys, secrets, and certificates. Microsoft Learn

VNet1 is also included in Defender for Cloud security posture management. Microsoft explicitly documents that Defender for Cloud analyzes Azure networking resources and generates security recommendations for virtual networks, subnets, network interfaces, NSGs, overly permissive traffic rules, and related network controls. The Microsoft support matrix lists Azure Virtual Network, including subnets, NICs, and NSGs, as receiving Defender for Cloud security recommendations. Microsoft Learn

The important distinction is that a VNet does not have a dedicated paid workload-protection plan analogous to Defender for Servers or Defender for Storage. It is nevertheless protected and assessed through Defender for Cloud CSPM capabilities.