Attributed to 'Magnallium' (AKA APT 33), by the Dragos Security Team (and commented on by Robert M. Lee - CEO of Dragos Security); and detailed at Wired by the inimitable Andy Greenberg...

'"I've not seen any capability by them to be able to cause significant disruption or destruction on infrastructure," Lee says.' - Robert M. Lee, CEO of Dragos Security and quoted in a brief interview by Andy Greenberg at Wired