Stop us if you're heard this one before: You're just about to start a workout at the gym and you notice your phone's barely holding on at 10% battery. Good thing you brought your charger to plug into a nearby outlet, right?

Unfortunately, your personal information is a lot more vulnerable while charging than you might think: Cyber attackers can steal your personal information from a compromised outlet or USB port without you even knowing it, CNN reports.

"Just by plugging your phone into a [hacked] power strip or charger, your device is now infected, and that compromises all your data," Drew Paik, who represents security firm Authentic8, told CNN.

The reason? The same cables that you use to charge your phone can also be used for sending data, like uploading photos to your PC. Hackers can take advantage of this feature in a common cyber attack known as "juice jacking."

While juice jacking is a relatively easy way of stealing personal information, most people aren't aware of this exploit; Paik told CNN that 80% of visitors to the RSA Security Conference who used their chargers didn't ask whether or not they were secure.

If you're wondering how to prevent "juice jacking," you have two options: The first (and simplest) option is to simply bring your own portable charger and avoid using an outlet or USB port altogether. If you're adamant on using your wall charger, you could alternatively buy a device like LockedUSB, which attaches to the USB end of your charging cable and shuts off the data transfer while you charge.