“National security authorities, in collaboration with relevant departments, have launched a nationwide special operation to address this issue,” it said.
The statement said hundreds of the devices had been seized and the individuals involved were penalised.
The ministry did not name the foreign organisations, but claimed they had deployed the devices in provinces surrounding the Bohai Sea, East China Sea and South China Sea.
“These devices are not only capable of stealing civilian aviation data but they can also intercept sensitive military aviation information,” it said.
According to the statement, the devices can be used to collect information from aircraft flying nearby, such as the type, location, speed and direction. It said this data was being sent to computers controlled by the foreign groups.
It warned that any organisation or individual transmitting data to foreign entities was engaging in an illegal activity that endangered national security.
The devices are believed to be able to cover an area of 300km to 400km (186 to 248 miles) – meaning that if they were located across the country then 300 of them would be enough to monitor China’s entire airspace.
China warns military buffs not to photograph classified equipment
China warns military buffs not to photograph classified equipment
The spy agency also said that when a number of the illegal devices were being operated at the same time they posed “a significant threat to Chinese aviation safety by causing signal interference with both civilian air traffic control and military air control systems”.
The functions of the devices could also “evolve” since they can be programmed remotely, according to the ministry.
“It’s estimated that each device can send about 1,000 instances of flight data and approximately 130,000 location data points abroad daily,” it said.
They receive the ADS-B signals – including location, altitude, identification codes, flight rate and vertical speed – used by civilian aircraft.
The ADS-B system facilitates data exchanges between aircraft without ground-based equipment, helping to detect potential route conflicts and prevent collisions.
These signals are available to anyone with a receiver – similar to tuning in to a radio station. The data is mainly used by platforms like Flightradar24 and VariFlight to collect and provide flight information.
China lashes out at ‘ill-intentioned foreign forces’ over its anti-spying law
China lashes out at ‘ill-intentioned foreign forces’ over its anti-spying law
But when large amounts of data are aggregated, they hold significant intelligence value through data mining technologies, according to a mainland Chinese expert who requested anonymity.
“This raises concerns, especially devices developed by foreign companies where the software and hardware are not open-sourced, as these devices could potentially upload other sensitive data,” he said.
“Multiple ADS-B receivers, if strategically placed, could even potentially form a passive radar system. So to eliminate risks, it’s imperative to regulate imported radio receiving devices – and particularly their data transmission to foreign entities.”
