Asiasoft discovered last Thursday that data including user IDs, passwords, names and residential registration numbers had been taken, according to the Korea Herald, though only South Korean user accounts were compromised.
"We operate separate servers in each country," a spokesperson said. "Only Korean's users' information was affected."
It means 72 per cent of MapleStory's 18 million South Korean players had their accounts stolen. While passwords were encrypted, Asiasoft recommends that users change their login details on other websites as a precaution. It has reported the breach to local telecoms regulator the Korea Communications Commission, and asked police to investigate.
Asiasoft hopes to raise around $1.3 billion in an initial public offering, to be filed in Tokyo early next month.
