Researchers have finally cracked Fast16, mysterious code capable of silently tampering with calculation and simulation software. It was created in 2005—and likely deployed by the US or an ally.

Photo-Illustration; Jobanny Cabrera: Getty Images

In the history of state-sponsored hacking , the spectrum of cyber operations bent on sabotage have ranged from crude “wiper” attacks that destroy data on target computers to the legendary Stuxnet , a piece of malware the US and Israel first deployed in Iran in 2007 to silently accelerate the spinning of nuclear enrichment centrifuges until they destroyed themselves.…