Automatic OS upgrades for windows are not enabled in Azure Virtual Machine Scale Set, this may leave it vulnerable to malware and other threats.
In Azure Console -
In Terraform -
Deprecated in favor of azurerm_linux_virtual_machine_scale_set and azurerm_windows_virtual_machine_scale_set:
References:
https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/virtual_machine_scale_set#automatic_os_upgrade