An agency of the Federal government (probably the CIA) is attempting to fiddle with Apple software, perhaps in retaliation for Apple's refusal to agree to include "backdoors" in their software. If Apple won't agree to a backdoor within it's software where it can be found by any government agency (ignoring that others can find it, also), then the agency will break in and covertly insert a backdoor after the software has become available for purchase - not only risking user privacy, but also placing at risk the reputation of Apple software. Who wants to buy corrupted software?
"Last week, Researchers disclosed some 39 iOS apps on Apple's App Store infected by 'XCodeGhost Malware'. The Bad News is that the infection has now increased exponentially with the discovery of more than 4,000 infected apps."
From the Hacker News link