A photo published in a Brazilian newspaper clearly showed the network's SSID and password.
Columbia University's Jason Nieh and Nicolas Viennot found thousands of secret keys being stored in app software.
The file management and optimization app is capable of sending SMS messages to premium rate numbers without the user's consent.
The admin capabilities of a mobile security management solution from Marble Security impressed reviewer Matt Sarrel.
Most mobile security solutions utilize a traditional endpoint management approach, but not the cloud security service provided by startup Armor5.
The market exceeded $1 billion in 2013, according to Infonetics.
43 percent of North American enterprise employees have accessed sensitive corporate data on their personal devices while on unsecured public networks.
The malware was found in six different wallpaper apps, each of which had been downloaded between 100 and 500 times.
During the same period, the total number of mobile malware samples surged from 189,626 to 299,950, according to Kaspersky Lab.
The app was briefly the top new paid app on Google Play, but it did nothing at all.
A Tripwire survey also found that 30 percent of IT professionals haven't changed their wireless routers' default passwords.
The company says 12.7 percent of all apps on Google Play in 2013 were malicious, up from just 2.7 percent in 2011.
The malware is designed to steal text messages and block incoming phone calls from specific numbers.