The international scientific community has defined a Stuxnet deadly weapon because been designed with a detailed analysis of final target environment supported by a meticulous intelligence work. The agent was designed with the intent to strike the Iranian nuclear program and even more clear is who has always opposed such a program, U.S. and Israel first, and consider also the technology skill necessary to develope a weapon with the observed architecture is really high. The ability to compose its structure at different times using modules designed specifically for precise goals, makes this unique and formidable.”]
Source: https://securityaffairs.co/wordpress/3487/malware/face-to-face-with-duqu-malware.html