Researchers, Serge Egelman, and Joel Reardon from AppCensus back in October last year reported to Google about a piece of code found in some popular android apps that are spying on its users.
Google took a while to investigate its claims and only took action in March this year.
The apps in question mostly consist of Quran, Muslim prayers, and unity apps and according to data, they have been downloaded more than 60 million times.
Reardon published their findings in detail on the AppCensus blog.
The researchers believed that the culprit is a system development kit (SDK) made by Measurement Systems, a company registered in Pana that is registered by a company called Vostrom Holdings, a firm based in Virginia with ties to the national defence industry.
The Wall Street Journal reported that app developers told them that they were paid to use the SDK and the company was most interested in data of those in the Middle East, Central and Eastern Europe, and Asia.
While the offending code has been disabled, these apps are still out there.