(Radio Iowa) – Most Iowans have been in an airport, shopping mall or movie theater, realized their phone battery was low, and plugged it into one of those free public chargers. Now, the F-B-I is warning about what’s being called “juice jacking,” where bad actors use those chargers to infect smartphones, tablets and other devices with malware. Consumer protection advocate Micheal Domke says that malware can be malicious.

Domke says “The perfect way to avoid that is to use your own cable, and if possible, use your own charger box and cable with it.” There are warning signs your device may have already been infected, and Domke says you need to stay vigilant to keep your private data private.  “You’re going to see that maybe you can’t get into some of your apps, maybe the password has changed,” Domke says. “Or unfortunately, a big indicator is maybe you log into one of your bank accounts or a credit card account and you see that there’s new charges or missing funds.”

Skimming devices placed inside U-S-B ports will allow a hacker to quickly access your banking apps, contacts, emails and texts within seconds. He recommends never using a public charger, but to instead, plug your own cord into a separate electrical outlet.