McLean, Va. — Hilton Hotels confirmed this week that it has been a victim of security breach. The news was confirmed following a two- month investigation of unauthorized malware that targeted payment card information in some point-of-sale systems. The company has since further strengthened its systems.

Brian Krebs, an independent cybersecurity journalist, caught wind that payment card terminals at the company’s restaurants, bars, and gift shops may have been compromised, reports Fortune.com.

Hilton did not reveal how many properties might be affected or how many customers’ credit card or debit card information might have been stolen, but it did say that “no addresses, personal identification numbers (PINs) or Hilton HHonors account information” were included in the potentially stolen information.

In an official statement, Hilton urges customers to “review and monitor their payment card statements if they used a payment card at a Hilton Worldwide hotel over a seventeen-week period, from Nov. 18 – Dec. 5, 2014, or April 21to July 27, 2015.”

Hilton Worldwide maintains it is strongly committed to protecting customers’ payment card information, and that they sincerely regret any inconvenience this may have caused customers.