Bitcoin dropped to a more than four-month low in persistent bearish trend.
Bithumb said 35 billion won worth of virtual coins were stolen by hackers, the second local exchange targeted in just over a week.
With a tech-savvy population quick to adopt latest gadgets and facing dim prospects in conventional workplace, S Korea has been a fertile ground for virtual currencies.
Bitcoin has found unlikely allies in Asia: regulators. Tokyo has officially recognised bitcoin and crypto-currency exchanges, and Seoul is mulling the same.