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.