Prosper Market Data Breach Affects 17.6M Individuals

Breach Notification Service Details Peer-to-Peer Lending Marketplace Victim Count Mathew J. Schwartz (euroinfosec) • October 17, 2025

Hackers appear to have stolen personal information pertaining to more than 17 million individuals from peer-to-peer lending marketplace Prosper.

A copy of the stolen data obtained by Have I Been Pwned, a free breach notification service, shows the hackers obtained 17.6 million unique mail addresses.

Exposed data included a customer's or prospective customer's name and date of birth, contact information including physical and email addresses, Social Security numbers, as well as details of an individual's credit status, employment and income.

Have I Been Pwned, run by Australian developer Troy Hunt, said that 2.8 million of the exposed email addresses were new to the service, meaning they never appear to have been exposed in a data breach, or at least one that came to light publicly. The ...