(Credit: US Secret Service)
A rogue cellular network secretly operating in the New York City area was likely used by foreign state-sponsored hackers, according to federal investigators.
On Tuesday, the US Secret Service announced it had dismantled a network of “100,000 SIM cards across multiple sites” in the New York tristate area.
The SIM cards were packed into more than 300 SIM servers located at different sites. Secret Service uncovered the network “following multiple telecommunications-related imminent threats directed toward senior US government officials this spring,” the agency said in a video. This included “fraudulent calls.”
CNN reports the calls involved “swatting threats” against US lawmakers, causing police to send SWAT teams to respond to fake hostage or shooting situations. The swatting calls also targeted lawmakers outside of New York, including Florida Republican Sen. Rick Scott and US Rep. Marjorie Taylor Greene of Georgia.
The Secret Service posted photos of the SIM servers, which were installed on racks in one location and in the corner of a room at another. At least some of the SIM servers were found in an empty rented apartment outside New York City.
(Credit: US Secret Service)CNN adds: “Officials briefed on the investigation say the electronic safe houses were found in places like Armonk, New York; Greenwich, Connecticut; even in Queens, New York; and across the river in New Jersey – essentially forming a circle around New York City’s cellular network infrastructure.”
In addition, some of the SIM cards were reportedly registered to MobileX, according to the carrier's CEO Peter Adderton. "We have strong safeguards in place to detect and block automated or bulk usage," he wrote in a tweet. "We shut down suspicious activity every day and are prepared to fully cooperate with authorities if contacted."
Federal investigators have been examining the SIM servers and the communication data sent to identify the culprits. “Early analysis indicates cellular communications between nation-state threat actors and individuals that are known to federal law enforcement,” the Secret Service says.
The same network could also be used to disable cell towers, “enabling denial of services attacks and facilitating anonymous, encrypted communication between potential threat actors and criminal enterprises,” the agency adds.
The Secret Service also noted the SIM servers were “concentrated within 35 miles of the global meeting of the United Nations General Assembly now underway in New York City,” suggesting a rogue network could have also posed a threat to international relations. However, some security experts have called out the Secret Service for exaggerating the threat.
"The Secret Service is lying to the press. They know it’s just a normal criminal SIM farm and are hyping it into some sort of national security or espionage threat," wrote the cybersecurity researcher Robert Graham. "What they discovered was just normal criminal enterprise, banks of thousands of cell “phones” (sic) used to send spam or forward international calls using local phone numbers."