Bitcoin extends losses following the hack of the South Korean crypto exchange Coinrail.

Bloomberg reports Bitcoin Tumbles Most in Three Months Amid South Korea Hack.

Bitcoin extended losses for a third day, tumbling 12 percent Sunday as South Korean cryptocurrency exchange Coinrail said there was a "cyber intrusion" in its system.

The largest cryptocurrency declined to $6,749 as of 2 p.m. in New York, the biggest drop since March 14, according to data compiled by Bloomberg from Bitstamp pricing. That widens Bitcoin's losses for the year to 53 percent. Peer cryptocurrencies Ethereum and Ripple fell 11 percent and 12 percent, respectively.

Coinrail said in a statement on its website that it's reviewing its system due to hacking attempts. The exchange says it has managed to freeze all exposed NPXS, NPER and ATX coins, and that other cryptocurrencies are now being kept in a cold wallet.

$40 Million Hack

Techcrunch reports Korean crypto exchange Coinrail loses over $40M in tokens following a hack

Another day, another crypto hack. This time it's Korea, the crypto-mad Asian country, where an exchange called Coinrail lost more than $40 million in altcoins, ICO-issued tokens that aren't bitcoin or Ethereum, after it was hit by an apparent attack over the weekend.