Zaif cryptocurrency exchange suffered a hot wallet breach on September 14, 2018 when attackers gained access to private keys storing customer funds. Approximately 5,966 Bitcoin, unspecified Bitcoin Cash, and MonaCoin totaling 6.7 billion yen (~$60 million) were stolen from the exchange's operational wallets. Discovery occurred three days after the theft.

Hackers with unauthorized access to the exchange’s hot wallets had stolen roughly $60 million in bitcoin, bitcoin cash, and MonaCoin. That being said, the exact amount of bitcoin cash stolen remains unknown.