The malware is remarkable both for its sweep  in computer jargon, it has not been merely “phishing” for random consumers’ information, but “whaling” for particular important targets  and for its Big Brother-style capacities. It can, for example, turn on the camera and audio-recording functions of an infected computer, enabling monitors to see and hear what goes on in a room. The investigators say they do not know if this facet has been employed.

The researchers were able to monitor the commands given to infected computers and to see the names of documents retrieved by the spies, but in most cases the contents of the stolen files have not been determined. Working with the Tibetans, however, the researchers found that specific correspondence had been stolen and that the intruders had gained control of the electronic mail server computers of the Dalai Lama’s organization.

The electronic spy game has had at least some real-world impact, they said. For example, they said, after an e-mail invitation was sent by the Dalai Lama’s office to a foreign diplomat, the Chinese government made a call to the diplomat discouraging a visit. And a woman working for a group making Internet contacts between Tibetan exiles and Chinese citizens was stopped by Chinese intelligence officers on her way back to Tibet, shown transcripts of her online conversations and warned to stop her political activities.

The Toronto researchers said they had notified international law enforcement agencies of the spying operation, which in their view exposed basic shortcomings in the legal structure of cyberspace. The F.B.I. declined to comment on the operation.

Although the Canadian researchers said that most of the computers behind the spying were in China, they cautioned against concluding that China’s government was involved. The spying could be a nonstate, for-profit operation, for example, or one run by private citizens in China known as “patriotic hackers.”

Image The Toronto academic researchers who are reporting on the spying operation dubbed GhostNet include, from left, Ronald J. Deibert, Greg Walton, Nart Villeneuve and Rafal A. Rohozinski. Credit... Tim Leyes for The New York Times

“We’re a bit more careful about it, knowing the nuance of what happens in the subterranean realms,” said Ronald J. Deibert, a member of the research group and an associate professor of political science at Munk. “This could well be the C.I.A. or the Russians. It’s a murky realm that we’re lifting the lid on.”