A few months after the hysteria around Stuxnet had died down, officials in Iran announced in April that some sensitive systems in the government s networks had been attacked by a new piece of malware, known then as Stars. It now appears that attack was, in fact, the first appearance of an early version of Duqu, the most recent in a line of sophisticated attack tools that experts say have been designed to take out specific targets in a variety of sensitive networks. Duqu appears to be a customizable attack framework that can be modified for any number of purposes by the individual attacker.
Source: https://threatpost.com/stars-attack-iran-was-early-version-duqu-110511/75857/