The Coincheck hack follows at least three multi-million dollar heists in 2017 including USD 63 million at NiceHash
The heist surpassed the attack on MtGox exchange in 2014 when hackers ran off with digital currency worth USD 480 million. The breach had forced the Tokyo-based company to shut down its operations and file for bankruptcy in the US and Japan.
The high-profile demise of MtGox failed to douse the enthusiasm for virtual currencies in Japan, which in April, last year, became the first country in the world to proclaim it as legal tender.
Nearly one-third of global Bitcoin transactions in December were denominated in yen, according to specialist website jpbitcoin.com.
The NEM coins stolen from Coincheck were stored in a "hot wallet" instead of the more secure "cold wallet", which operates on platforms not directly connected to the internet, Coincheck said. It also does not use an extra layer of security known as a multi-signature system.
Coincheck said on Sunday it would return about 90 percent with internal funds, though it has yet to figure out how or when.
However, the incident angered Japan's financial regulator and it raided the cryptocurrency exchange. The regulator had warned that it would inspect all exchanges in the country.The Coincheck hack follows at least three multi-million dollar heists in 2017 including USD 63 million at NiceHash.
NiceHash borrows and lends mining power and facilitates the mining of cryptocurrencies for its users. About 4,700 Bitcoins were stolen from wallets on its server in a hacking attempt on December 6, last year and the services were stopped for over 24 hours. The top brass of the company had to apologise to the users in a Facebook live stream.The CEO of the company Marko Kobal had to resign and NiceHash got a new chief in form of Zdravko Poljašević.