After denying the accusation that it deliberately included backdoor services in iOS for potential data collection by third-parties, Apple has followed up this denial with a new support document that details several backdoor services and their legitimate uses.
The services described by Apple include:
com.apple.mobile.pcapd: pcapd supports diagnostic packet capture from an iOS device to a trusted computer. This is useful for troubleshooting and diagnosing issues with apps on the device as well as enterprise VPN connections. You can find more information at developer.apple.com/library/ios/qa/qa1176.
com.apple.mobile.file_relay: file_relay supports limited copying of diagnostic data from a device. This service is separate from user-generated backups, does not have access to all data on the device, and respects iOS Data Protection. Apple engineering uses filerelay on internal devices to qualify customer configurations. AppleCare, with user consent, can also use this tool to gather relevant diagnostic data from users' devices.
com.apple.mobile.house_arrest: house_arrest is used by iTunes to transfer documents to and from an iOS device for apps that support this functionality. This is also used by Xcode to assist in the transfer of test data to a device while an app is in development.
Details on several iOS backdoor services originally were published by Jonathan Zdziarski as part of a presentation during the Hackers On Planet Earth (HOPE/X) conference. You can view all of Zdziarski's presentation slides here: (PDF)
[Image from EFF Photos]