At this time DuQu does not propagate and has been released only within targeted industries, although Symantec admits it may also be elsewhere and not yet discovered. The original compile dates on some of the variants of DuQu so far analyzed suggest it may have existed as far back as November 3, 2010. Stuxnet compile dates were between June 2009 and March 2010 and therefore pre-date DuQu.

Download PDF
http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/w32_duqu_the_precursor_to_the_next_stuxnet.pdf

"Duqu" Removal Tool:

You only have to download and run it on the system, then reboot the PC if infection is found. Here is a complete rundown of the steps you need to take:
1. Download the Duqu_Removal_Tool.zip (.zip file), then double-click on it chose "Extract all files..." from the File menu, and follow the wizard's instructions. You can use any other decompression utility, like WinZip.
2. Navigate to the folder you have extracted the tool in, find the file called Duqu_Removal_tool.exe and double-click on it. Press the Scan button and let the removal tool scan your PC.
3. If you have Windows Vista with User Access Control enabled, or if you are running as a restricted user in Windows XP, right click the Duqu_Removal_tool.exe program and choose "Run as Administrator". You will be prompted to enter credentials for an admin account.
4. Press the OK button when the removal tool asks for a reboot.
5. If you don't already have permanent antivirus protection or if your current antivirus has failed you, consider using the advanced protection tool provided by BitDefender.

Download
http://www.duquremoval.com/files/Duqu_Removal_Tool.zip