McAfee was discovered malware targeting Windows users inside an Android app promoting Kentucky Fried Chicken (KFC) on Google Play, most probably embedded by accident by a careless developer unaware of its existence.
The security firm's researchers noticed the generic worm 'og!ats' bundled inside the APK file associated with the promotional app 'KFC WOW@25'. The malware can't do any harm to an Android device and the chances of Windows users being infected would be vanishingly small although it might be possible if they downloaded it to a Windows PC and attempted to open the APK as a Zip.
"When a legitimate Android application contains a malicious file such as this one (for a Windows PC), it is likely this has occurred due to neglect on the part of the developer. This neglect can be as simple as not securing the development environment," suggested McAfee's Fernando Ruiz in a blog.
It was possible that the developer was using out-of-date antivirus software, "so without realizing that the computer was infected, the source code directory contained a copy of the worm," he speculated.
"From there the worm was packaged, signed, and deployed on Google Play, with the developer completely unaware of the file."
The application had been withdrawn from Google Play, he said.
"The lesson for developers is clear. It is vital to remember the essentials for a secure computer: maintain updated antimalware software, especially if you intend to distribute content to other users."
The discovery of the polluted Android app underlines the risks to users on the Play app store, a place on which they are supposed to feel secure.
A week ago Symantec said it had found 1,200 problematic apps on Google Play in seven months, some of which survived for download for several days. At times, it can seem as if security companies are performing some of the malware-spotting role that should be carried out by Google itself.