1. A computer program product embodied in a computer readable medium that, when executing on one or more computers, reduces scanning requirements of a primary virtual machine based on an understanding of a related virtual machine, by performing the steps of: in response to a change in the primary virtual machine, comparing the primary virtual machine to the related virtual machine and tracking changes of the primary virtual machine with respect to the related virtual machine wherein the changes are identified by location within the primary virtual machine, forming a tracked changes log; generating a relevant file map of the primary virtual machine wherein the relevant file map includes a plurality of relevant files and each of the plurality of relevant files' locations in the primary virtual machine; comparing the changed locations identified in the track changes log with the locations of the plurality of relevant files to determine if any one of the plurality of relevant files has been changed; and in the event that a relevant file has been changed, as indicated by the comparison of the relevant file map to the tracked changes log, causing the changed relevant file to be security scanned.