In July 2014, U.S. users of CryptoPhone 500 noticed something odd: a smattering of fake cell towers, known as “interceptors”, attempting to trick cellular phones into revealing data. But the story was more concerning than that. Under normal circumstances, your cell phone connects to a nearby cell tower, which has a name. In the case of these nameless interceptor towers, not only were CryptoPhones automatically forced to connect, but their phones’ encryption were shut down, allowing the towers access to unencrypted data on the phone.
It was later discovered that these towers were operated by the federal government by organizations such as the NSA. And it doesn’t stop there; even local law enforcement agencies are getting in on the snooping action through the use of StingRays. These devices not only capture cell phones’ IMSI numbers, which can be used to identify individual owners of cell phones, but they can also be used to spy on phone calls and text messages. At least 18 states have these types of towers, which mimic common carriers like AT&T and Verizon. Since then, these types of stories have ignited further privacy concerns over cell phones and what information they make available, especially in light of NSA surveillance.
In response, Security Research Labs recently published SnoopSnitch, an Android-based cell phone app that discovers and alerts users to connecting interceptor towers.
“SnoopSnitch is an Android app that collects and analyzes mobile radio data to make you aware of your mobile network security and to warn you about threats like fake base stations (IMSI catchers), user tracking and over-the-air updates. With SnoopSnitch you can use the data collected in the GSM Security Map at gsmmap.org and contribute your own data to GSM Map,” according to the company’s website.
Tower location information is collected and mapped by the many users of SnoopSnitch, and available to see through the phone app. According to users, there is not enough information collected to produce a map in the U.S.
Right now, SnoopSnitch is only available for phones with Qualcomm chipsets running the Android phone platform.