The National Security Agency has placed software on nearly 100,000 computers around the world that allows it to conduct covert surveillance on the machines, the New York Times reports.
The technology gives the agency access to private computer networks yet could also create a virtual highway for cyberattacks, the Times said in a story published on its website Tuesday.
The agency describes its efforts as part of an "active defense" against foreign cyberattacks rather than an offensive tool. But U.S. officials have protested when similar software was discovered to have been placed on computers in this country by Chinese attackers.
"What's new here is the scale and the sophistication of the intelligence agency's ability to get into computers and networks to which no one has ever had access before," James Andrew Lewis, the cybersecurity expert at the Center for Strategic and International Studies in Washington, told the Times.
The report said most of the software is inserted into individual computers by gaining access through computer networks. But citing agency documents and computer experts, it said the NSA has also made use of secret technology that allows it to enter or alter data even in computers not connected to the Internet.
The technology, in use since 2008, uses a covert channel of radio waves that can be transmitted from small circuit boards and USB cards inserted secretly into the computers by a spy, manufacturer or unwitting user, the Times reported.
In some cases, the newspaper said, the agency makes use of briefcase-size relay stations positioned to collect the data from a target.
Partnering with the Pentagon, the agency has frequently targeted the Chinese army, which the U.S. government has accused of regularly launching digital attacks on industrial and military targets, the report said.
The newspaper said the program, code-named "Quantum," also placed software into Russian military networks and systems used by police and drug cartels in Mexico. Other targets include European trade institutions and even foreign allies like Saudi Arabia, India and Pakistan.
It said there is no evidence that the NSA has placed its software or used its radio technology inside the United States. While refusing to comment on the scope of the Quantum program, the NSA told the Times its actions were not comparable to China's.