1. An apparatus for performing frequency-based classification of executable objects, comprising: a hardware platform comprising a processor communicatively coupled to a memory; a network interface; and a reputation client engine to operate on the hardware platform, and configured to: parse an executable object into a plurality of subroutines; assign a pseudo-unique identifier to a subroutine; find subroutines with the same pseudo-unique identifier having previously-calculated execution frequencies; aggregate the execution frequencies of the subroutines; assign an execution frequency score to each subroutine according to the aggregated execution frequencies; provide the execution frequency scores to a service via the network interface; and receive via the network interface a reputation score for the executable object based at least in part on the execution frequency scores of the subroutines of the executable object.