Trading platform Robinhood has revealed that personal information of more than seven million customers has been accessed during a data breach.
An unauthorised third-party socially engineered a customer support employee by phone and obtained access to certain customer support systems of the stock-trading app last week.
"At this time, we understand that the unauthorised party obtained a list of email addresses for approximately five million people, and full names for a different group of approximately two million people," the company said in a statement late on Monday.
The attack has been contained and according to the company, no social security numbers, bank account numbers, or debit card numbers were exposed and "that there has been no financial loss to any customers as a result of the incident".
"We also believe that for a more limited number of people -- approximately 310 in total -- additional personal information, including name, date of birth, and zip code, was exposed, with a subset of approximately 10 customers having more extensive account details revealed," the trading platform revealed.
Hackers demanded an extortion payment and according to Robinhood, it informed law enforcement and was continuing to investigate the incident with the help of cyber security firm Mandiant.
"As a Safety First company, we owe it to our customers to be transparent and act with integrity," said Robinhood Chief Security Officer Caleb Sima.
"Following a diligent review, putting the entire Robinhood community on notice of this incident now is the right thing to do," Sima said.
The breach took place late on November 3.