Can a virtual machine be stolen if it is not connected to the Internet?

Yes Because the virtual machine itself is an application running on the physical computer, it depends on the hardware and operating system of the physical computer and the software installed on the physical computer. The physical computer where the virtual machine is located has been networked, and the virtual machine can access Internet resources, so the virtual machine is at risk of being attacked and stealing information. So there is no virtual opportunity to steal information.