Four years after security researchers first revealed that cell-site simulators—also known as IMSI catchers or Stingrays—were potentially hidden across Washington, D.C., fears resurfaced this week that foreign governments could be using the spy technology to track or monitor citizens' mobile communications in the city.
For years, privacy advocacy groups have warned that the use of the surveillance devices have been shrouded in too much secrecy. In the U.S., IMSI (international mobile subscriber identity) catchers are typically purchased and used by law enforcement—including the FBI, the Drug Enforcement Administration and Immigration and Customs Enforcement—to monitor the cellphone chats of targets. Some campaigners warn, however, that the tech also endangers the privacy of civilians not suspected of any crime.
"IMSI catchers, and their use by law enforcement, has been controversial for some years, especially in the U.S., not least as their use was initially kept hidden," cybersecurity researcher Robert Pritchard told Newsweek. "They allow for capturing details of all mobile phones in a certain area, which enables law enforcement to easily see who is in a crowd or to identify individuals' localized movements."
The snooping process is simple. The device works by posing as a legitimate cell tower and searching for phones in the proximity of the device. By using a stronger signal than a real tower has, it dupes devices in its radius to connect to it, giving the operator the ability to record key information and intercept chats.
'10,000 phones'
The Electronic Frontier Foundation (EFF) says the system violates "basic constitutional protections."
"Police can use cell-site simulators to try to find a suspect when they already know their phone's identifying information, or to scoop up data on anyone in a specific area," the organization explains. "Some…are small enough to fit in a police cruiser, allowing law enforcement officers to drive to multiple locations, capturing from every mobile device in a given area—in some cases up to 10,000 phones at a time."
The EFF says Stingrays "invade the privacy of everyone who happens to be in a given area, [although] the vast majority have not been accused of committing a crime." While costs vary, leaked brochures published by The Intercept in 2015 suggest the surveillance tech—at least one model—can reach six figures.
"Without oversight, the use of Stingrays further erodes the privacy of anyone using a cellphone or wireless internet from their homes, regardless of the level of encryption in use," Jeff Bardin, chief intelligence officer for cybersecurity company Treadstone 71 and a former Air Force cryptologic linguist, told Newsweek.
"The unauthorized use of these devices or the use of these devices by foreign state actors allows for direct interrogation of cellular devices and the complete extraction of all data on these devices," he continued. "This could lead to the placement of malicious or eavesdropping software on cellular devices for continued monitoring and data extraction. The use in Washington, D.C., would represent a major breach of protocol and access to countless government conversations meant to be secure.
"If these devices have been replicated by foreign actors, which is likely they have, the use of them in the United States is probably widespread," Bardin added. "There needs to be more transparency on these devices and their use."
Spy Games
The discovery of suspected IMSI catchers placed in sensitive areas of the nation's capital was alarming for Democratic Senator Ron Wyden, who said last year it could "pose a significant threat to our country's national and economic security." Computer experts agree, warning that the consequences of abuse could prove to be severe.
"Both IMSI catchers and rogue cell towers have become commodity technology that any motivated person can assemble using open-source software and very cheap hardware," Ang Cui, chief scientist of Red Balloon Security, told Newsweek.
"Like many other offensive cybertechnologies, these two capabilities have percolated down from nation-states to your common cybercriminal and script kiddie," he continued. "When IMSI catchers were a controlled capability, the discussion of privacy made sense. The reality of it now is that this technology is widely accessible, and criminals will use it regardless of what privacy-preserving policies we enact. Like every other cyberweapon, we will not be able to legislate the use of this technology away, certainly not from [use by] criminals and foreign intelligence."
