Having recently needing to register a *.cloudapp.net domain for a proof of concept subdomain takeover, I was faced with one issue — how does someone register a *.cloudapp.net domain in 2019? Microsoft sunsetted it’s classic portal in early 2018.
After playing around with the standard Azure Portal, I quickly realized there was no apparent way to register a Classic Azure VM, the virtual machine type tied to the *.cloudapp.net domain. Despite there still being a “Virtual Machines Classic” section under all services in the Azure Portal, Microsoft has merged the two Virtual Machine categories into one.
After some searching I discovered “Microsoft Azure Xplat CLI”. By logging in with “azure login” and then setting it’s mode to ASM (Azure Service Manager) via “azure config mode asm” you can use the “azure vm create” command, which allows you to create Classic Azure VMs. Thus giving you a *.cloudapp.net domain.