The men stole confidential information that helped them profit on the stock market, prosecutors say.
Three Chinese hackers have been ordered to pay $8.8m (£6.8m) over a multi-million dollar insider trading scam.
The US Securities Exchange Commission (SEC) said Iat Hong, 26, Bo Zheng, 30, and Hung Chin, 50, breached the websites of US law firms and accessed confidential information about mergers and acquisitions.
They then used this information to profit on the stock market.
The men, who have not been extradited, were fined in their absence.