FirstFinancial Holding Co. Ltd.'s banking and brokerage units fought offan attack from unidentified hackers that partially affected its online servicesSept. 22.

FirstSecurities Inc. and First Commercial Bank Co. Ltd. received an email fromhackers asking for a ransom of 50 bitcoins to protect their electronic tradingsystems from attacks, Taipei Times reportedSept. 24, citing a filing from First Financial to the Taiwan Stock Exchange.

The companies detected a distributed denial-of-serviceattack Sept. 22 that resulted in a slowdown of their online services. FirstSecurities said it was still able to process clients' market orders despite theattack. The company finished blocking malicious IP addresses involved in theattack by 7:30 p.m. Taiwan time the same day.

First Commercial Bank restored its retail and corporateonline banking services the same day.

Taiwan's Financial Supervisory Commission said the incidentwas an isolated one and that no other threats or disruptions were found inother financial firms. Prosecutors are already looking into the case, the FSCsaid.