Up to 4.6 million users of the Android smartphone operating system have downloaded a suspicious wallpaper app that collects and transmits user data to a site in China, mobile security firm Lookout has warned.
The firm said in a blog post that although the Jackeey Wallpaper app's gathering of data, including the device's phone number, is suspicious there is no evidence of malicious behaviour
"There have been cases in the past on other mobile platforms where well-intentioned developers are simply over-zealous in their data gathering, without having malicious intent," the blog post said.
Speaking at this week's Black Hat security conference in Las Vegas, Kevin MaHaffey, chief technology officer at Lookout, said Jackeey Wallpaper is an example of the wider risk faced by smartphone users.
Apps that seem good but are really stealing your personal information are a big risk at a time when mobile apps are exploding on smartphones, he said.
MaHaffey said users have to pay attention to what they download, and developers have to be responsible about the data they collect and how they use it, according to US reports.
Lookout discovered the suspicious behaviour of Jackeey Wallpaper as part of research in its App Genome Project aimed at making people aware of the capabilities of mobile apps.
Mobile applications on all platforms - Android, iPhone, Blackberry, and Symbian - can potentially gather sensitive data from users, the researchers have found.
Lookout has called on all mobile application users and developers to act responsibly.
Android maker Google said it has suspended the Jackeey Wallpaper app while it investigates the matter.