OSX/XcodeGhost is malware delivered as a compromised version of Apple's XCode Interactive Development Environment (IDE) to unsuspecting app developers. It secretly infects apps built with the IDE to spread malware to end user iOS and OS X devices. These malware apps are capable of spying on users and stealing user information [1]. PaloAlto networks provided a technical analysis of the novel infection technique [2].

References:

1. https://en.wikipedia.org/wiki/XcodeGhost
2. https://researchcenter.paloaltonetworks.com/2015/09/novel-malware-xcodeghost-modifies-xcode-infects-apple-ios-apps-and-hits-app-store/