Despite the truth of your historical timeline, 'WannaCry' does neatly fit the profile of Room 39, a department of the North Korean government which raises foreign currency through cybercrime and other criminal activities [0][1]. They have been implicated in past hacks by non-U.S. groups as well, including Kaspersky Labs [2].

[0] https://www.washingtonpost.com/world/asia_pacific/he-ran-nor... [1] https://en.wikipedia.org/wiki/Room_39#Purpose_and_activities [2]http://money.cnn.com/2017/04/05/news/economy/north-korea-eco...