In case the Iranian discussion is still ongoing there might be another clue here…
Duqu hackers scrub evidence from command servers, shut down spying op

The hackers behind the Duqu botnet have shut down their snooping operation, a security researcher said today.

The 12 known command-and-control (C&C) servers for Duqu were scrubbed of all files on Oct. 20, 2011, according to Moscow-based Kaspersky Lab.
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Duqu was designed, said Symantec and Kaspersky, by advanced hackers, most likely backed by an unknown country’s government. Unlike Stuxnet, it was not crafted to wreak havoc on uranium enrichment centrifuges, but to scout out vulnerable installations and computer networks as a lead-in to the development of another worm targeting industrial control systems.
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Duqu has been traced to attacks in several countries other than Iran, including the Sudan, and may have been under construction since August 2007.

Looks like maybe they’ve collected all the info they needed and closed up the operation.