SitusAMC, a company that provides back-end services for top banks and lenders, disclosed on Saturday a data breach it had discovered earlier this month that impacted customer data.

As a real-estate (commercial and residential) financing firm, SitusAMC handles back-office operations in areas like mortgage origination, servicing, and compliance for banks and investors.

The company generates around $1 billion in annual revenue from 1,500 clients, some of whom are banking giants like Citi, Morgan Stanley, and JPMorgan Chase.