Apple has removed 250 apps from its store after discovering a widely-used advertising network was siphoning off private information such as email addresses in breach of the company’s policies.
The apps, which are largely from Chinese-based developers, all used a software development kit (SDK) called Youmi to build in advertising. But, apparently unknown to the developers, Youmi also built in code that would steal user data and upload it to Youmi’s own servers.
The problem with Youmi’s code was first discovered by researchers from Purdue University, but gained attention when independently reported by research firm SourceDNA, which highlighted the fact that the malicious apps were the first that it had seen successfully bypass the app review process.
At the heart of the issue is Youmi’s use of private APIs, commands which are built into iOS by Apple but which third-party developers are prohibited from using for reasons ranging from security to stability. Youmi’s code called four such commands: to receive the serial number of the device, the list of installed apps, the serial numbers of any peripherals, and the user’s Apple ID.
In a statement, Apple said: “We’ve identified a group of apps that are using a third-party advertising SDK, developed by Youmi, a mobile advertising provider, that uses private APIs to gather private information, such as user email addresses and device identifiers, and route data to its company server. This is a violation of our security and privacy guidelines.
“The apps using Youmi’s SDK will be removed from the App Store and any new apps submitted to the App Store using this SDK will be rejected. We are working closely with developers to help them get updated versions of their apps that are safe for customers and in compliance with our guidelines back in the App Store quickly.”
Combined, SourceDNA estimates that the apps have over 1 million downloads.
This article was written by Alex Hern, for theguardian.com on Tuesday 20th October 2015 09.55 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010