Wiktionary
killbot
n. (context scifi English) A robot designed to kill; a robotic assassin.
Wikipedia
Killbot (band)
Killbot is an American electronic dance music trio formed in January 2012. The lineup includes JDevil ( Jonathan Davis of Korn and Jonathan Davis and the SFA fame), and Sluggo (Nick Suddarth). Killbot's music is a fusion of dubstep, electro, drum and bass, and moombahton.
Usage examples of "killbot".
But as long as some technical part of society could hold out, eventually we'd get them through genano diseases attacking their bodies or nanotech killbots attacking their machines.