Well, my thoughts were more along the lines of the malicious software somehow needs to make it onto the infected host and then must be reliably controlled. How

Well, my thoughts were more along the lines of the malicious software somehow needs to make it onto the infected host and then must be reliably controlled. How do you write/test scripts which are so reliable to work across all the different types of devices, networks, OS etc which participated in this attack? To infect and control this many devices your code must be rock solid.