NEW YORK Industrial and Commercial Bank of China's (ICBC) hack left its US unit temporarily owing Bank of New York Mellon US$9 billion  as a result of unsettled trades, prompting the parent to inject capital into the unit to settle the trades, sources familiar with the matter said.

BNY has since been paid back, the sources said.

The attack, confirmed by ICBC on Thursday, is the latest in a string of ransom demands by hackers this year. ICBC Financial Services, the bank's US unit, said on Thursday it was investigating the attack that disrupted some of its systems, and making progress towards recovering from it.

ICBC’s representatives told market participants on a call organised by industry group the Securities Industry and Financial Markets Association earlier on Friday that it has hired a third party to make sure its systems are safe, sources said.

ICBC did not respond to requests for comments. 

  - Reuters