FBI warns people to avoid public USB chargers

Charging phones could leave with them software that monitors their users, law enforcement warns

(AFP via Getty Images)

Free charging stations could leave phones filled with software that monitors their users, the FBI has warned.

The US law enforcement agency warned users not to charge their devices using free charging stations in public areas, that offer a USB connection.

Such outlets are intended as easy ways to charge devices in places such as hotels or airports. But they can also be easy ways for criminals to install unwanted software onto a device, the FBI warned.

“Avoid using free charging stations in airports, hotels or shopping centers. Bad actors have figured out ways to use public USB ports to introduce malware and monitoring software onto devices,” it said in a tweet.

“Carry your own charger and USB cord and use an electrical outlet instead.”

In a similar warning on its website, the FBI warned against using public Wi-Fi networks for similar reasons. “Do not conduct any sensitive transactions, including purchases, when on a public network,” it warns.

USB plugs can get access to the files that are stored on a phone, laptop or other device, as well as being able to send filed back. That means that anything plugged into the that port, such as a charging wire or a USB thumb drive, can quickly steal information or take over a device.

Once that happens, attackers may have access to large parts of the system, potentially being able to see sensitive personal information or steal money.

Some devices – such as iPhones – include security features that are intended to stop such attacks. They must be unlocked for data to be sent down the cable, for instance, and the phone will ask whether the user “trusts” the device they are plugged into.

The FBI did not give any indication of whether the warning had been released as a result of any specific or new threat.