Hackers can use public USB chargers to steal personal data. Here’s what you need to know about ‘juice jacking’

We all know the feeling of panic when your mobile phone is about to die when you're out and about – and the feeling of relief when you find a convenient place to give it a power boost.

But security experts are urging people to think twice before plugging in. “Juice jacking” – or using public USB connections to introduce malware to smartphones and other devices – is an increasingly popular ploy by cyber criminals.

Travellers are advised to stop charging their mobile phones and devices at public USB charging points like those found at airports and hotels because of the risk they present. The Los Angeles District Attorney recently issued a warning about fraud due to USB charger scams.

“A free charge could end up draining your bank account," Deputy District Attorney Luke Sisak warns, adding the malware has the ability to lock devices and share passwords with hackers.

The vulnerability of USB chargers, combined with the rise in sophisticated malware targeting smartphones, is something security experts have warned against for some years. Back in 2016, the FBI issued a nationwide warning after one particular piece of hardware, KeySweeper, was used to steal keystrokes from nearby wireless keyboards.

USB cables left in charging points are particularly risky, drawing in people who may not be carrying their own cable.

A recent report from security software firm BlackBerry highlighted the risks our mobile phone opens us up to. Hackers take advantage of the fact we tend to be more trusting of these devices than we are of desktop computers. The report cites espionage campaigns that have targeted Pakistan’s military and government through fake apps.

There are a few steps you can take to keep your mobile phone or device charged and safe on the move – including investing in a USB condom. These small devices prevent cables from transferring data, and limit them to accessing the power source.

Other tips include making sure your device is fully charged before you go out, using standard plug power outlets rather than USB charging stations and using portable, personal chargers for emergencies.