Bithumb, the world's fourth largest cryptocurrency exchange by volume, confirmed a security incident during which an unknown hacker was able to make off with an yet undetermined amount of funds.
Clues that something was wrong emerged on Thursday, when South Korean users, who make most of Bithumb's userbase, started complaining on a local social network about losing control over large funds stored in their Bithumb accounts.
A day later after these complaints, the company officially admitted the breach in a blog post on its website, albeit it did not provide any meaningful details.