Flame, as the espionage tool has been named, is a -- 20 to 40 times larger than Stuxnet -- that infiltrates networks, scouts out the digital landscape, then uses a variety of modules to pilfer information.

What researchers are trying to determine is not only how Flame works -- an effort that will take months -- but how it fits with other malware that experts believe targeted Iran, a country at odds with the West over its nuclear program.

In particular, two earlier-discovered threats: Stuxnet, which most have concluded was created to sabotage Iran's uranium-enrichment facilities, and Duqu, an intelligence-gathering tool many believe was used to pinpoint targets for Stuxnet.

"The most interesting thing about Flame is its possible relationship to Stuxnet," said Roel Schouwenberg, a senior researcher with Moscow-based antivirus company Kaspersky Lab. "The timelines [of the two] will play a big part in any analysis."

Liam O Murchu, director of operations for Symantec's security response center, agreed. "The timeline is very important," said O Murchu.