The stolen information included the value of some customers’ portfolios and details of their stock trades, but did not involve the company’s personal payments system.
Sensitive information for more than eight million users of Cash App Investing — a stock trading app run by Block, the owner of the Square payments system — was exposed when a former employee downloaded corporate reports after leaving the company. Block revealed the data exposure in a regulatory filing on Monday, and said it was contacting the affected customers. “Upon discovery, we took steps to remediate this issue and launched an investigation with the help of a leading forensics firm,” Fiona Lee, a Block spokeswoman, said. “We know how these reports were accessed, and we have notified law enforcement.” The exposed data involved only users of Cash App’s investing product, not the person-to-person payment service with roughly 44 million users, the company said. The information was retrieved by the former employee in December and included customers’ names and Cash App brokerage account numbers.
