Examples perform external verification of authenticity of software components loaded onto virtual machines (VM). A processor, external to the VM, reads the loaded software component from the VM, and restores the loaded software component to its disk image state by undoing any changes made to load the software component. The digital signature is read from the restored disk image of the software and compared to the verified digital signature of the publisher of the software component. Some examples contemplate marking the software component as verified or unverified, and preventing unverified software components from making global changes.