Miller built a fake stock ticker app, dubbed "Instastock," as a proof-of-concept, then submitted it to Apple, who approved and placed it in the App Store in September.
Instastock exploited the bug Miller discovered to ping a server at his home and request to download another file. While Miller did not stock his server with such a file -- except briefly for demonstration and testing purposes -- it proved the app could secretly download rogue code. Such "malware" could conceivably issue commands to an iPhone or iPad, stealing contacts and photos, turning on the device's camera or microphone, or sending text messages.
