No evidence that this alleged attack was highly-targeted, but it is pretty much SOP now, since the history of Stuxnet [1] publicly revealed the strategy. I was initially impressed the Bloomberg's story, but the longer this drags on with no independent proof, and given the one of the author's previous infosec reporting gaffe with no follow through, I've dismissed the story's veracity to a low probability.

[1] https://en.wikipedia.org/wiki/Stuxnet#History

No evidence whatsoever. Just all speculation based on previous targeted malware attacks that are public knowledge.