While not as large as some other trading platforms, Coinrail still ranks amongst the world's top 90 digital currency exchanges.
Bitcoin was one of those affected, falling 10 percent to its lowest price in two months. That brings Bitcoin's losses for the year to about 52 percent.
Coinrail said in a statement on its website that some of the exchange's digital currency appears to have been stolen by hackers, but it did not quantify the value.
Enthusiasm for virtual currencies has waned partly due to a string of cyber heists, including the almost $500 million theft from Japanese exchange Coincheck Inc.in late January. The rest of the coins were then moved to a safe "cold valet", which is disconnected from the internet.
"The heist at Coinrail, a relatively small South Korean cryptocurrency exchange, sent the price of bitcoin tumbling to two-month lows as it once again highlighted the security risks and the weak regulation of global cryptocurrency markets".
The largest cryptocurrency declined 5% to $7 247 as of noon in NY, the biggest drop since May 23, according to data compiled by Bloomberg from Bitstamp pricing.
The Korean National Police Agency didn't immediately reply to a request for comment. The nation's cleanup of initial coin offerings and Bitcoin exchanges has nearly been completed, the newspaper said, citing Sun Hui, an official at the Shanghai branch of the central bank.
Coinrail did not specify the value of the currency that was taken in the attack at the weekend but said it was working with authorities and other coin developers to track down the culprits. South Korea's Omnitel Inc. and Vidente Co. both retreated at least 4%, while Japan's Remixpoint Inc. slumped about 6%.
On the ground in Singapore ahead of the Trump-Kim summit
The White House said the daylong summit would also include a working lunch and a larger meeting involving aides to both leaders. Traffic was held up in the steamy midday sun and scores of bystanders were penned in by police when Trump went to meet Lee.
Trump told Macron EU worse than China on trade
The EU trade surplus with the U.S.is $151 Billion, and Canada keeps our farmers and others out. "And that ends", Trump said. Lindsey Graham (R-S.C.) said Sunday on ABC's "This Week", "I'm not so sure John's right about where America is on trade".