Mysterious fake mobile phone towers discovered across America could be listening in on unsuspecting callers.
A report by Popular Science says the towers have been discovered across the country, and have the ability to attack mobile phones through eavesdropping and installing spyware.
They were discovered by people using a heavily customised Android device called the CryptoPhone 500.
It uses a secure version of the software which can tell if the phone is being subjected to what is known as a baseband attack.
It is then possible to trace the location of the offending tower.
The fake cell towers were detected in July, but the report states there could be more.
Les Goldsmith, chief executive of security firm ESD America, told the magazine: “Interceptor use in the US is much higher than people had anticipated.
“One of our customers took a road trip from Florida to North Carolina and he found eight different interceptors on that trip. We even found one at a casino in Las Vegas.”
He said several of the masts were situated near US military bases.
“What we find suspicious is that a lot of these interceptors are right on top of US military bases,” he said.
“So we begin to wonder – are some of them US government interceptors? Or are some of them Chinese interceptors?
“Whose interceptor is it? Who are they, that’s listening to calls around military bases? Is it just the US military, or are they foreign governments doing it? The point is: we don’t really know whose they are.”