The threats represented an imminent threat to the agency’s protective operations.

The Secret Service said this protective intelligence investigation led to the discovery of more than 300 co-located SIM servers and 100,000 SIM cards across multiple sites.

In addition to carrying out anonymous telephonic threats, these devices could be used to conduct a wide range of telecommunications attacks, the agency said.

The attacks included disabling cell phone towers, enabling denial of services attacks and facilitating anonymous, encrypted communication between potential threat actors and criminal enterprises.

While forensic examination of these devices is ongoing, early analysis indicates cellular communications between nation-state threat actors and individuals that are known to federal law enforcement.

“The potential for disruption to our country’s telecommunications posed by this network of devices cannot be overstated,” said U.S. Secret Service Director Sean Curran. “The U.S. Secret Service’s protective mission is all about prevention, and this investigation makes it clear to potential bad actors that imminent threats to our protectees will be immediately investigated, tracked down and dismantled.”

Was UNGA the target of the attack?

The Secret Service said these devices were concentrated within 35 miles of the global meeting of the United Nations General Assembly, now underway in New York City.

The investigation into the incident is currently ongoing.