Former Expedia worker Jonathan Ly has admitted to hacking his own chief financial officer and investor relations head to commit US$331,000 in insider stock-trading.

Ly, 28, of San Francisco, pleaded guilty to securities fraud in a Seattle District Court and faces up to 25 years prison and a US$375,907 settlement including some US$81,592 in repayments for expenses Expedia incurred during its investigation.

All told Ly is said to have made US$331,000 in net profit through the securities trades.

The former senior support technician used his remote login credentials and those of others he was supplied during his job to access the data.

Prosecutors say he also used the credentials of other employees to mask his intrusions.

Ly is accused of stealing the information over the three years to 2016 including market speculation about pending announcements which helped the hacker gain an edge in his share trading efforts.

Prosecutors say Ly continued to plunder Expedia after he voluntarily left the company last year using software loaded onto a corporate laptop still in his possession.

CNN reports that Ly's lawyer, John Runfola, says his client is "deeply sorry" and has "certainly learned his lesson".

Sentencing is scheduled for 28 February. ®