A computer-implemented virtual applicant appliance (VAA) and method for managing migration of an application on a source computer to a virtual application within the VAA on a target computer networked to the source computer are disclosed. The VAA includes resources on the target computer, a virtual application for execution in the VAA, and network credentials for remotely connecting to the source computer and copying data resources from the source computer. A runtime intercept of the VAA compares on-demand resource requests of the virtual application to resources on the target computer and provides the requested resource to the virtual application. When the runtime intercept fails to locate the requested resource in the resources on the target computer, a tether of the VAA remotely retrieves the requested resource from the source computer using the network credentials and then copies the requested resource into the resources on the target computer.