Let’s be honest: I spend more time playing games on my smart phone than talking on it. Our phones have become our family photo albums, personal gaming systems, calendars, encyclopedias, navigators, and instant messengers. If you can think of an activity, there’s probably an app for it.

Unfortunately, some apps might not be what they claim, and downloading the wrong app could put your phone on the fritz. According to the FTC, that’s what happened to thousands of people who downloaded the Prized app before it was removed from the app store.

Prized claimed that users could earn prizes by completing tasks like playing games and taking surveys. Instead, the app contained malware that hijacked the phone’s computing power. As a result, phones ran slower, had less battery life, and used up people’s data plans.

What were the defendants doing with the combined computing power of all those phones? They were using it to mine virtual currencies, like Dogecoin and Litecoin. Virtual currencies are created on peer-to-peer networks through a competitive process called “mining.” As more people join the network, the challenge of mining gets tougher. Miners need faster and more advanced computing to make a profit.

In this case, the defendants were using the power of the hijacked phones to mine for their own profit — but the Prized app didn’t tell people that or get their okay. That’s why the FTC and the Office of the New Jersey Attorney General brought charges against them. The settlement requires the defendants to pay civil penalties and prohibits them from creating and distributing malicious software.

So, what can you do to avoid downloading malware to your phone?

  • Before you download an app, check out reviews and research the developer. Also, review the permissions that an app requires.
  • If your phone seems to be running slowly, heating up, or losing battery power quickly, check your settings to see which apps are using your data and battery power. If you have apps that are using unreasonable amounts of data and power, consider removing them.
  • If your phone isn’t working properly, you also might want to contact customer support for the company that made the phone or your mobile service provider.