The researcher in question, Barnaby Jack, today told the Ruxcon Breakpoint security conference in Melbourne, Australia that "the most obvious scenario would be a targeted attack against a high profile individual."
Jack also warned of a worst-case scenario "worm with the ability to commit mass murder".
Such devices are accessible through a wireless interface designed to deliver telemetry and allow maintenance. But Jack, who works for US-based security company IOActive, has subverted security in that interface and showed delegates a video demonstration of a wireless attack against an Implantable Cardioverter-Defibrillator (ICD). "There's 830 volts going into the heart there, which is a bummer," he said as an audible zap played over the conference audio system.
The attacks work at a range of up to 50 feet.