US hotel chain Hilton revealed Tuesday that hackers infected some of its point-of-sale computer systems with malware crafted to steal credit card information.

Hilton would not disclose whether data was taken, but advised anyone who used payment cards at Hilton Worldwide hotels between November 18 and December 5 of last year or April 21 and July 27 of this year to watch for irregular activity on credit or debit card accounts.

Malicious code that infected registers at hotels had the potential to take cardholders’ names along with card numbers, security codes and expiration dates, Hilton said in an online post.

Source: Hilton hotels hit by cyber attack