It seems to be quoting a tweet by Jacob Appelbaum. I think that the idea could be that they don't know who put the malware there. As this person was an activist, it's possible that it was there by the government this person was opposing. How does the Angolan government treat activists?

I imagine that if a similar thing happened to an Egyptian activist during Mubarak's time in power that it would not be such a stretch to say such a thing.