Fast16 Malware Manipulated Nuclear Weapons Simulation Data to Sabotage Test Results

Fast16 is described as a highly targeted, nation‑state style malware that hooked into LS‑DYNA and AUTODYN physics solvers to subtly alter simulated pressure/density outputs—making nuclear weapon simulations appear subcritical and misleading weapons engineers. Cited timeline artifacts and analyses (leaks, VirusTotal upload, SentinelOne and Symantec research) place its compilation around 2005 and suggest deliberate, sustained targeting of uranium implosion simulations; attribution remains unconfirmed but is speculated to involve US/Israeli actors or close allies.