Long before Stuxnet's centrifuges spun out of control in Natanz, a Lua-based framework called Fast16 was already targeting the digital heart of nuclear weapons design. Symantec's latest dissection, building on SentinelOne's earlier work, shows the malware selectively sabotaged uranium compression simulations inside LS-DYNA and AUTODYN only when material densities exceeded 30 g/cm³—the precise threshold for implosion-device modeling. This was not generic industrial espionage; it was precision sabotage of R&D outputs. The 101 hook rules, grouped to track version updates across at least ten builds, reveal operators who monitored software patches and adapted in real time, forcing researchers to downgrade versions only to be hit again. Evidence tying Fast16 to the Equation Group via a 2017 Shadow Brokers leak places the capability inside NSA-linked tooling as early as 2005—two years before Stuxnet 0.5. Cross-referencing with Kim Zetter's reporting on early Equation Group tradecraft and declassified assessments of pre-2010 cyber operations against Iranian and North Korean programs shows a consistent pattern: Western intelligence prioritized corrupting simulation fidelity over kinetic strikes. What original coverage missed is the operational tempo—Fast16's self-spreading and AV-evasion logic implies it was deployed inside air-gapped or high-security networks years before public Stuxnet awareness, suggesting sustained access rather than one-off campaigns. This reframes Stuxnet not as the origin of cyber sabotage against nuclear programs but as the public culmination of a decade-long effort to degrade adversary R&D at the simulation layer.