Russia-based security vendor, Kaspersky Lab, claims to have found the first malware to appear on Apple's App Store.
The "Find and Call" app, which was also available in Google's Android app store, was uploading the contact lists of users to a remote server, and sending out SMS spam to the harvested numbers. The SMS messages would contain a link to download the infected application.
At first, it was thought to be an SMS worm spread through text messages, rather than via the app store, but it has since been diagnosed as a trojan.
Find and Call has since been removed from both the App Store and Google Play.
Malware on Google Play is nothing new, but this would be the first time that an app containing malware has appeared in the Apple App Store.
Apple is famous for its stringent guidelines in the approval and release of apps in its App Store.
The electronics vendor has also been dealing with technical issues that caused updated apps from the App Store and Mac Store to refuse to work, following the update. Apple is working to fix the problem.
ZDNet Australia is awaiting comment from both Apple and Google.