McDonald's has lost thousands of customer details to a hacker, including names, phone numbers and street and email addresses. The fast food chain is also warning of pending phishing scams.
The customer details were lost after a hacker broke into the fast-food restaurant's US marketing partner and stole the details provided by customers who sign up for promotions.
McDonald's was concerned that the hacker might use the details to conduct phishing scams. Phishing scams are fraudulent email campaigns run by criminals to steal financial and identity information, or infect users computers with malware.
"In the event that you are contacted by someone claiming to be from McDonald's asking for personal or financial information, do not respond and instead immediately contact us … McDonald's would not ask for that type of information online or through email," the company wrote on its website.
"Law enforcement officials have been notified and are investigating this incident."
The company apologised for the breach.
McDonald's spokesperson Bronwyn Stubbs said Australian customers were not affected.
An email provider hired by promotion company Arc Worldwide was responsible for the loss, which did not include credit card data or social security numbers.