An anonymous reader writes "On Oct. 14, 2011 Symantec was alerted to a malware sample from some recovered computers that demonstrated code similar to Stuxnet. This code however appears to serve a different purpose, apparently laying the groundwork for a future Stuxnet type of attack."
Quoting Symantec: "The threat was written by the same authors (or those that have access to the Stuxnet source code) and appears to have been created since the last Stuxnet file was recovered. Duqu's purpose is to gather intelligence data and assets
from entities, such as industrial control system manufacturers, in order to more easily conduct a future attack against another third party. The attackers are looking for information such as design documents that could help them mount a future attack on an industrial control facility."