UPDATED: The firmware sent text message contents, call data and app usage details to Shanghai, researchers found
The handsets, including low-end devices sold online by Amazon and Best Buy, transmitted data including the full body of text messages, contact lists, call history with telephone numbers, unique device identifiers and other data to servers owned by the firmware’s maker, Shanghai AdUps Technology, according to Kryptowire.
The devices affected include the BLU R1 HD, a popular device marketed by Amazon in the US, Kryptowire said.
AdUps said it designed the firmware for Chinese phone manufacturers and carriers to help them track customer behaviour for advertising purposes. The code is built into models sold by Huawei, ZTE and others intended for the Chinese market, and was included in the BLU devices by mistake, the company said.
BLU is a Miami-based company that has sold low-end devices in the Americas for decades and has recently expanded its US operations.
An attorney for AdUps told the New York Times the data was not being collected for the Chinese government, stating AdUps was “a private company that made a mistake”.
It collected and transmitted details about the use of applications, executed remote commands with system-level privileges and had the capability to remotely reprogram devices.
Text message and call log data were sent to the server every 72 hours, with information including location and app use details sent every 24 hours.
BLU said in a statement the backdoor affected only a “limited number” of its devices, and said those devices have since been updated to remove the functionality.
The company told the Times about 120,000 devices were affected.
UPDATE: Huawei has denied its handsets used the firmware
“We take our customers’ privacy and security very seriously, and we work diligently to safeguard that privacy and security,” a spokesperson told TechWeekEurope. “The company mentioned in this report is not on our list of approved suppliers, and we have never conducted any form of business with them.”