Duqu first came to light in September, but it may have been circulating four or five months before that. Its customizable, modular architecture has been a challenge for researchers seeking to understand its operation and its creators intentions. Threatpost editor Dennis Fisher spoke with Costin Raiu, one of the main researchers working on Duqu at Kaspersky Lab, about the relationship between Stuxnet and Duqu, the possible identity of the attackers and the investigation into its architecture. Every single component of Duqu was written to make it very hard to detect by itself.
Source: https://threatpost.com/anatomy-duqu-attacks-112111/75916/