The App Store has been hacked by an unknown person (or group) to purchase apps created by “Thuat Nguyen.” Some users are reporting that hundreds of dollars are being spent on books, causing the apps in question to jump to the top of the “Top Apps” page. This is bad for both users and developers, whose apps are being pushed down off the Top Apps page, leading to decreased sales.
This issue is widespread, affecting users in the United States and UK at the very least, and most likely the rest of the world. Make sure to check your iTunes account for any malicious activity, and to be safe unlink your credit card. It looks like Apple support hasn’t done much, and most people are having better luck resolving the issue through their credit card company or bank.
This wouldn’t be the first time Apple users have had their accounts hacked, so stay vigilant and try to catch any suspicious activity before it causes too much damage.