Kaspersky Lab researchers conclude that Stuxnet and Duqu worm share common origins. Both share a common design, featuring identical division of the programs into parts carrying out similar functions. Researchers also found seven other similar drivers with similar characteristics. They conclude that they were either connected to an earlier version of Duqu or fragments from unidentified pieces of malware created by the same team in the period 2007-2011. The evolution of the malware suggests that this development is ongoing and has affected its targets in ways not yet detected or made public.”]
Source: https://www.csoonline.com/article/2130579/stuxnet-and-duqu-part-of-larger-cybermalware-campaign.html