NEW YORK — Luxury merchant Neiman Marcus confirmed Saturday that thieves stole some of its customers’ payment card information and made unauthorized charges over the holiday season, becoming the second retailer in recent weeks to reveal it had fallen victim to a cybersecurity attack.
The hacking, coming weeks after Target Corp. revealed its own breach, underscores the increasing challenges that merchants have in thwarting security threats. Neiman Marcus didn’t say whether the breach was related to the massive data theft at Target, but some security experts believe they could be part of the same scam.
In any case, the recent security breaches at two major retailers threaten to scare shoppers who worry about the safety of their personal data.
Ginger Reeder, spokeswoman for Dallas-based Neiman Marcus Group Ltd., said in an e-mail Saturday that the retailer had been notified in mid-December by its credit card processor about potentially unauthorized payment activity after customer purchases at stores.
On Jan. 1, a forensics firm confirmed evidence the upscale retailer was a victim of a criminal cybersecurity intrusion and some customers’ credit and debit cards were possibly compromised.
Reeder wouldn’t estimate how many customers may be affected but said the merchant is notifying those whose cards it has determined were used fraudulently.
Neiman Marcus, formerly known as Neiman-Marcus, operates more than 50 upscale stores and clearance stores.
It is working with the Secret Service on the breach, Reeder said. ‘‘We have begun to contain the intrusion and have taken significant steps to further enhance information security,’’ she wrote.
Robert Siciliano, a security expert with McAfee, a computer security software maker, says it is possible Neiman Marcus doesn’t yet know the extent of the breach. He says he believes that the two thefts were likely committed by the same organized group, based on his experience and the fact that the incidents happened at around the same time.
Target disclosed Friday that its massive data theft was significantly more extensive and affected millions more shoppers than the company announced in December. The nation’s second-largest discounter said hackers stole personal information — including names, phone numbers, e-mail, and mailing addresses — from as many as 70 million customers as part of a data breach it discovered last month.
The Minneapolis-based Target announced Dec. 19 that some 40 million credit and debit card accounts had been affected by a data breach that happened from Nov. 27 to Dec. 15 — just as the holiday shopping season was getting into gear.
As part of that announcement, the company said customers’ names, credit and debit card numbers, card expiration dates, debit-card PINs, and the embedded code on the magnetic strip on the back of cards had been stolen.
According to new information gleaned from its investigation with the Secret Service and the Department of Justice, Target said Friday that criminals also took non-credit-card related data for some 70 million customers. This is data Target obtained from customers who, among other things, used a call center and offered their phone number or shopped online and provided an e-mail address.
Some overlap exists between the 70 million individuals and the 40 million compromised credit and debit accounts, Target said.
When Target releases a final tally, the theft could become the largest data breach on record for a retailer, surpassing one uncovered in 2007 that saw more than 90 million records pilfered from TJX Cos. Inc.