Fast16: Pre-Stuxnet Sabotage Tool Was Built to Subvert Nuclear Weapons Simulations

Key findings

Fast16’s hook engine is selectively interested in high-explosive simulations inside LS-DYNA and AUTODYN.

All evidence suggests that attackers were specifically targeting simulations of nuclear detonations. The malware checks for the density of the material being simulated and only acts when that value passes 30 g/cm³, the threshold uranium can only reach under the shock compression of an implosion device. Up to ten distinct software builds carry tailored hooks, suggesting a sustained operation that tracked target organisations' software updates over years.

The t…