The database of credit card customers at upscale American department store Neiman Marcus was hacked in December.
Marcus confirmed that its database of customer information was hacked last month, independent security researcher Brian Krebs reported.
According to CNET, online Neiman Marcus shoppers have reportedly not been affected by the hacking so far, only retail shoppers.
Ginger Reeder, a spokesperson for Dallas-based Neiman Marcus, told Krebs that details on the hack are sparse, the report said.
The cause, size, and duration of the attack are currently unknown, it added.
