Hacking of Trading Accounts in Japan Spreads to Mid-Sized Firms

Criminals have targeted mid-sized brokerages in Japan after the country’s biggest securities firms added additional protection for online trading.

Okasan Securities Co. and Iwai Cosmo Securities Co. both said they had been hit by fraudulent trading. Iwai Cosmo said a third party had gained access to client accounts and conducted illicit trades in Japanese equities. Okasan did not give details of what happened.