What is Virtual machine?

A virtual machine is a complete operating system running as software on top of a hypervisor, isolated from the host computer. It has its own virtual disk, memory and network.

For analysts, VMs are disposable workspaces. Malware can be detonated, risky sites visited and tools tested without touching the real machine, and snapshots allow a clean restart. Some malware checks whether it is in a VM and changes behaviour, which analysts have to account for.