A British-Nigerian man has confessed in a US court to defrauding and stealing more than $6m (£4.7m) over seven years.
Idris Dayo Mustapha, 33, was part of a hacking ring that infiltrated email and brokerage accounts of US firms between 2011 and 2018, causing losses worth $6m (£4.7m), officials said.
A dual national of the UK and Nigeria, Mustapha was extradited from the UK in August, two years after his arrest.
His crimes carry a jail term of up to 20 years.
He has not yet been sentenced.
Mustapha pleaded guilty plea at a court in Brooklyn, New York, on Tuesday to four charges: computer intrusion, securities fraud, wire fraud and access device fraud.
Authorities say Mustapha and his ring hacked into the computer servers of financial institutions in the US to access confidential user data, such as users' personal identifying information.
They then used the stolen information and passwords to wire funds and transfer securities from the accounts of their victims to accounts under their control.
They also used the hacked accounts to conduct stock trades without the knowledge of the account holder.
US authorities had been pursuing Mustapha for several years.
BBC