An unauthorized outside party accessed Bithumb's internal mobile groupware system, resulting in a leak of personal information

From the articleBithumb Investigates Extent of Data Leak After Internal HackAlso in Three South Korean financial firms including Bithumb report data breaches, Yonhap says | Reuters, Bithumb Says Intruder Took Personal Data From Internal Employee App, Trading Unaffected - Unchained, Bithumb Says Hackers Accessed Internal System, Leaking Personal Data - Decrypt, Cyberattack wave widens across Korean financial sector, Bithumb Confirms Breach as Hackers Hit 3 South Korean Financial Firms, Bithumb among three South Korean financial firms reporting data breaches, Bithumb hacked through employee system as South Korean financial firms face cyberattacks, Coinbase, Bithumb, Daishin, Mirae Asset hit by data leaks: What crypto users should know