spy vs. spy —

Feds: There are hostile stingrays in DC, but we don’t know how to find them

There’s also “anomalous activity”—probably stingrays—in other US cities, too.

US Capitol Building in Washington, DC.
Enlarge / US Capitol Building in Washington, DC.

The federal government has formally acknowledged for the first time that it has located suspected and unauthorized cell-site simulators in various parts of Washington, DC.

The revelation, which was reported for the first time on Tuesday by the Associated Press, was described in a letter recently released from the Department of Homeland Security to the offices of Sen. Ron Wyden (D-Oregon).

"Overall, [DHS' National Protection and Programs Directorate] believes the malicious use of IMSI catchers is a real and growing risk," wrote Christopher Krebs, DHS' acting undersecretary, in a March 26, 2018 letter to Wyden.

The letter and attached questionnaire say that DHS had not determined who is operating the simulators, how many it found, or where they were located.

DHS also said that its NPPD is "not aware of any current DHS technical capability to detect IMSI catchers." The agency did not explain precisely how it was able to observe "anomalous activity" that "appears to be consistent" with cell-site simulators.

The devices, which are also known as stingrays or IMSI catchers, are commonly used by domestic law enforcement nationwide to locate a particular phone. Sometimes, they can also be used to intercept text messages and phone calls. Stingrays act as a fake cell tower and effectively trick a cell phone into transmitting to it, which gives up the phone’s location.

Given that cell-site simulators have been used for years at home, it would be naive to think that malevolent actors, including criminals and foreign governments, would not attempt to set up stingrays in major American cities, particularly the capital.

DHS' answers also say that the agency is "aware" of the use of stingrays in other US cities, although it did not name them.


In 2015, various federal law enforcement agencies, including the FBI, said that, in most circumstances, they will require a warrant when they use a stingray. Some states also impose similar requirements.

In 2014, the Federal Communications Commission began a task force into the "illicit" use of stingrays in America, but the investigation doesn't appear to have produced any public reports or taken any meaningful actions.

Neither the FCC nor DHS immediately responded to Ars' request for comment.

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Channel Ars Technica