The aim was to "gain access to South African MFA [ministry of foreign affairs] network", to "collect intelligence from target machines" and to "find more access points to increase reliability".

In the corporate-tinged jargon that is pervasive at GCHQ, the desired "customer outcomes" did not involve any suspected nefarious activities by South African diplomats.

This was about spying on their normal work. The objective of the operation was described as acquiring "retrieved documents, including briefings for South African delegates to G20 and G8 meetings".

The primary ethical objection that the US makes about Chinese computer espionage (The APT) is that the purpose of US spying is to protect people's security whereas the purpose of Chinese spying is to gain leverage in economic negotiations - IE for a profit.

The use of a surveillance apparatus in the context of economic negotiations between peaceful nations is unethical. This isn't about protecting people from terrorist attacks - this is about making your friends rich.

I hope to god that the vast domestic surveillance infrastructure in the United States that was unveiled over the past few weeks is not being used by our own politicians to directly benefit the private economic interests of the corporations who fund their campaigns, against the interests of other Americans.

How GCHQ stepped up spying on South African foreign ministry | World news | The Guardian