That timeline generally fits with what Western security companies have said about their part in Flame's analysis.

According to Moscow-based Kaspersky Lab, its researchers were asked to investigate by the United Nations' International Telecommunication Union (ITU) after that agency received reports that an unknown piece of malware was deleting sensitive information on Windows PCs throughout the Middle East.

Iran first noted the attacks against its energy industry in late April, making it feasible that the country was able to craft a Flame detection tool within the next few weeks, as it claimed.

O Murchu said that Symantec's telemetry confirmed what other antivirus vendors have said: Iran harbors the largest number of Flame-infected systems.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at , on or subscribe to . His email address is .