Bitcoin prices plunged about 15 percent in Asian trade Wednesday before recouping some of the losses as investors apparently took fright at news that South Korean exchange Youbit had been hacked. According to multiple South Korean reports citing Seoul’s intelligence agency, North Korean hackers approach workers at digital exchanges by posing as beautiful women on Facebook, striking online conversations and eventually sending files containing malicious code. Citing the recent “speculative” escalation in prices across the crypto markets, the Monetary Authority of Singapore has released a statement advising the public to take “extreme caution” if investing in digital currencies such as bitcoin.