US-based retailer Forever 21 revealed Tuesday it suffered a recent data breach which was discovered by a third-party report.

The company said the report focused on transactions made in Forever 21 stores between March and October of this year. They didn’t provide in-depth details since the investigation is still ongoing.

The breach happened when encryption on point of sale devices at some stores stopped functioning. It resulted in unauthorized access to debit and credit card data.

Forever 21 owns 815 stores in 57 countries across the globe, and has not yet made it clear in which location the breach happened.