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Stop! Don’t Charge Your Phone This Way

A dead or dying phone or laptop is enough to send anybody on a mad dash to find a way to charge the device, but you might want to think twice before using that random cable found at an airport charging station or docking into that hotel USB port — hackers could be waiting.

As the busy holiday season approaches, the Los Angeles County District Attorney’s Office is warning travelers about a USB charger scam, or “juice jacking.”

“A free charge could end up draining your bank account,” Luke Sisak, a deputy district attorney, said in a video posted online this month.

Juice jacking happens when unsuspecting users plug their electronic devices into USB ports or use USB cables that have been loaded with malware.

The malware then infects the devices, giving hackers a way in. They can then read and export your data, including your passwords, and even lock up the gadgets, making them unusable.

Juice jacking exploits the fact that somebody doesn’t have a full battery, said Liviu Arsene, a cyber security expert at BitDefender, a Romanian cybersecurity and antivirus software company.

Mr. Arsene cautioned against using USB cables found already plugged into charging stations or even given away as promotional gifts.

“You can easily brand these things so you can make it look like any other cable,” he said, adding, “When people see it, they don’t really think or expect it to be malicious in any way.”

Other ways to protect yourself include carrying your own charging wires, only charging directly from an electrical outlet and using portable batteries that were bought from known vendors, Mr. Arsene said.

“Don’t believe everything you see, and don’t believe everything you get your hands on,” he said, noting that starting with Black Friday, if it looks too good to be true, it probably is.