Did you know that your smartphone and tablet can be infected with viruses and malware—just like desktop and laptop computers? This typically happens when you download a malicious app.

Once it is on your device, hackers can steal sensitive material such as account details, passwords and photos. They can cause your operating system to crash, rendering your device useless. They even can hijack your contacts list and send spam texts to your friends, family and associates. From 2013 to 2014, mobile app malware targeting Android phones rose by 600% globally to more than 650,000 different varieties.

How to protect your devices…

Get apps only from official websites. The official Apple iOS and Android app stores each offer more than a million apps to choose from. They do an excellent job of scrutinizing new apps and quickly weeding out malicious or infected ones. Nonofficial sites that offer unique apps or free versions of popular paid apps often have low security ­standards, and some may even be fronts for hacker groups. This is especially true for Android, which is installed on more than half of all mobile devices in the US. Unlike iOS, Android has an “open” operating system—smartphone and tablet manufacturers can alter the software to work on their devices. These altered systems can be more susceptible to hackers.

Helpful: If you have an Android device, make sure you don’t accidentally install unofficial apps. Go to the Settings menu, tap “Security,” then uncheck the “Unknown Sources” option. Also, avoid clicking on any link to an app that you receive in a text or an e-mail.

Install an antivirus/malware app. The Apple and Android app stores offer Lookout and other antivirus apps for free.