A Report by Jacob Appelbaum, Aaron Gibson, Claudio Guarnieri, Andy Müller-Maguhn, Laura Poitras, Marcel Rosenbach, Leif Ryge, Hilmar Schmundt and Michael Sontheimer based on Snowden Leaks Tells us about the efforts by British Governments GCHQ (Government Communications Headquarters) To Track The Targets by Their iPhones by a Fomous malware "WIRELURKER".
iPhone Software is Considered as Malware-Resistant Software but the new Documents leak show that even when the iPhone is'nt infected by the Malware, iPhone sync with the infected computer allow GCHQ Personals to surveil targets. GCHQ by watching the Target's Device UDID (Unique Device Identifier, which is a sequence of 40 letters and numbers that is specific to your device.), it could follow the same device data as it gets synced with infected computer, like Brwosing the web,AdMob. This
allow GCHQ People to Identify the person using it. In 2010, Apple has fixed this UDID issue making iPhones Immuse to these Surveillance.
Source : The Verge, Spiegel.de .