«

»

Nov
20

2013

Langner’s final Stuxnet analysis comes with surprises

Langner’s final analysis of the Stuxnet malware comes with several surprises that call for a re-assessment of Operation Olympic Games. The report, summing up three years of research and including plant floor footage from Natanz, comes with a comprehensive de-composition of Stuxnet’s “forgotten” attack against S7-417 controllers. It explains the attacked cascade protection system in detail and puts the two attacks in context, arriving at conclusions about shifting priorities during the operation.

Major surprises include:

  • The attack against the S7-417 is the ultimate in aggressiveness and stealthyness; without the later (and less sophisticated) Stuxnet variant that received so much public attention, it would never have been discovered
  • In the 417 attack, compromise is carried forward to the field level, manipulating sub-controllers for pressure control
  • During mission progress, the attackers went from complex and stealthy to simple and crude, accepting risk of discovery

The report also addresses common misconceptions about Stuxnet, such as the theory that the malware would have escaped from Natanz due to a programming error, or that nation-state capabilities would be required to pull off copycat attacks against critical infrastructure installations.

Last but not least, it is pointed out by an analysis of plant floor footage that Iran has changed the design of their centrifuge cascades to allow for dynamic reconfiguration by valves, which has implications on the time needed to break out of the IAEA regime and produce weapons-grade highly enriched uranium.

The full report (36 pages) is available for download. An abbreviated version appeared in Foreign Policy.