IOActive researcher Barnaby Jack has reverse-engineered a pacemaker transmitter to make it possible to deliver deadly electric shocks to pacemakers within 30 feet and rewrite their firmware.

The effect of the wireless attacks could not be overstated — in a speech at the BreakPoint security conference in Melbourne today, Jack said such attacks were tantamount to “anonymous assassination”, and in a realistic but worse-case scenario, “mass murder”.

In a video demonstration, which Jack declined to release publicly because it may reveal the name of the manufacturer, he issued a series of 830 volt shocks to the pacemaker using a laptop.

The pacemakers contained a “secret function” which could be used to activate all pacemakers and implantable cardioverter-defibrillators (ICDs) in a 30 foot -plus vicinity.

Each device would return model and serial numbers.

“With that information, we have enough information to authenticate with any device in range,” Jack said.

In reverse-engineering the terminals – which communicate with the pacemakers – he discovered no obfuscation efforts and even found usernames and passwords for what appeared to be the manufacturer’s development server.

That data could be used to load rogue firmware which could spread between pacemakers with the “potential to commit mass murder”.

“The worst case scenario that I can think of, which is 100 percent possible with these devices, would be to load a compromised firmware update onto a programmer and … the compromised programmer would then infect the next pacemaker or ICD and then each would subsequently infect all others in range,” Jack said.

He was developing a graphical adminstration platform dubbed “Electric Feel” which could scan for medical devices in range and with no more than a right-click, could enable shocking of the device, and reading and writing firmware and patient data.

“With a max voltage of 830 volts, it's not hard to see why this is a fairly deadly feature. Not only could you induce cardiac arrest, but you could continually recharge the device and deliver shocks on loop," he said.

Jack said his goal was not to cause harm, but to help manufacturers secure their devices.

“Sometimes you have to demonstrate the darker side," he said.