My understanding is that the ??someone?? trashed the Iranian nuclear program with stuxnet by sprinkling USB drives around the city where the centrifuges were located. Eventually, some worker found a free USB, and walked it into the building infecting their internal computers.

The virus (or worm,) infected around the network until it got to the PLCs that ran the centrifuges and had them run over speed and fail.

I mean, this shit is so easy. You can not run an election on USBs.