content: Right, you either need to get a clamp really close to the PSU (preferred) or the electrical panel  (noisy, but effective) to even detect the pulses.  And then you need to actually have the malware on the machine in order to produce the data to be interpreted by the receiver.  So you still need physical access to the machine at some point, and then you have to hope people maintaining the hardware (facilities electrical people or IT people) don't notice your fucking receiver clamped on somewhere between the machine and the electrical panel.  Or of course, notice the extra cores being activated by the presence of malware. This is definitely proof of concept; not scary implementation by a long shot.