The shopping site for Walmart, the largest U.S. retailer, is down after a security breach at the retailer’s headquarters in Fort Worth, Texas.
Walmart said Friday that it had been alerted by security analysts that a password had been compromised.
Walmart said that it was unable to immediately respond to the breach because of “ongoing investigations.”
The breach has affected approximately 4,000 employees, according to a Walmart news release.
A security analyst with the firm Mandiant said the company believed that the password was created in the previous year and that the company had never heard of it being used in the last six years.
The company said it had not been notified of a breach at any other of its facilities, but that it would be conducting a security assessment to determine if it had a similar breach.
The breach at Walmart comes at a time of heightened scrutiny over cyber threats posed by companies such as Target Corp. and Walmart, as well as government agencies and private companies.