https://www.theregister.co.uk/2017/08/30/north_korea_bitcoin_exchange_hack/

North Korea has emerged as the prime suspect in recent Bitcoin exchange hacks in South Korea, with threat intel experts warning that more attacks on digital currency services and even mainstream banks are likely to follow.

South Korea's Cyber Warfare Research Center reportedly believes that at least one Bitcoin exchange was targeted in a hack pulled off using a carefully crafted email phishing campaign.