1. A method for detecting malware in network traffic, the method comprising: executing, in an emulation environment, an executable file as it is being received serially over a network, the executing beginning once a block of data including an entry point of the executable file has been received, the executing halting whenever an instruction in the executable file references data not yet received and resuming once the data not yet received has been received, the executing ceasing upon satisfaction of a termination condition; examining the emulation environment for indications that the executable file includes malware; and taking corrective action responsive to results of the examining.