From darkreading.com
What a newly discovered missing link to Stuxnet and the now-revived Flame cyber espionage malware add to the narrative of the epic cyber-physical attack.
Three years after the 2010 discovery of the Stuxnet attack that sabotaged a uranium enrichment process at the Natanz nuclear facility in Iran, researchers at Symantec found what they surmised was a precursor to the known payload that caused the plant’s centrifuges to spin out of control and fail. This early version of Stuxnet, which they called Stuxnet .5, targeted the Siemens PLC control systems that operate the valves that feed uranium hexafluoride gas into uranium enrichment centrifuges. Stuxnet .5 could close the valves and halt the release of depleted and enriched uranium gases, damaging the equipment and the manufacturing process.
The discovery led Symantec’s researchers to revise their time frame of the Stuxnet attack to 2005, two years earlier than the known 2007 to 2009 attacks on the Natanz centrifuges, which were believed to be launched by the US and Israel to derail the possible development of nuclear weapons in Iran.