The world has grown accustomed to malware that steals your credit card information or demands bitcoin to access your files.

But a new hacker tool is targeting the safety systems at industrial plants around the world, according to a fascinating investigation in the MIT Technology Review — the same safety systems, ominously, that protect nuclear power stations and water treatment facilities.

“In a worst-case scenario, the rogue code could have led to the release of toxic hydrogen sulfide gas or caused explosions, putting lives at risk both at the facility and in the surrounding area,” wrote MIT Tech‘s Martin Giles of an incident when the malware was found to have attacked a petrochemical plant in Saudi Arabia.