Luxury retailer Neiman Marcus Group informed some customers last week that their online accounts had been breached by hackers.
According to the company, cybercriminals used an automated attack to try various username and password combinations in an attempt to gain access to customer accounts on Neiman Marcus, Last Call, Bergdorf Goodman, Horchow, and CUSP websites. The attack is said to have started on or around December 26.
The retailer said the hackers managed to access roughly 5,200 accounts, but highlighted that the username/password combinations had not been stolen from its systems. Instead, the company believes the attackers used credentials stolen from other breached organizations and attempted to abuse them knowing that many people use the same username and password for multiple online services.
“At present, all indications are that the Neiman Marcus Group database of customer email addresses or passwords remains safe, and that our cyber defenses repelled more than 99% of the attacks,” the retailer told affected customers.
The breached accounts contain customer names, contact information (mailing addresses or phone numbers), last four digits of saved payment card numbers, and purchase history. Social security numbers, dates of birth, full bank account numbers and PINs are not at risk, Neiman Marcus said.
The attackers used roughly 70 of the breached accounts to make unauthorized purchases on Neiman Marcus websites, but the retailer said its fraud team detected these purchases and reimbursed affected customers.
Neiman Marcus will require all impacted customers to change their account passwords next time they log in.
“We initiated a comprehensive response and investigation to understand the scope of the incident, and it appears that our defense functioned as designed during the attack. Our team has taken significant steps to limit the ability of these individuals to access Neiman Marcus accounts,” the company said in a data breach notice submitted to the California Office of the Attorney General.
This is not the first time Neiman Marcus customers have been targeted by cybercriminals. In January 2014, the company revealed that attackers might have stolen as many as 1.1 million customer payment cards using point-of-sale (PoS) malware. The company later said the breach only affected roughly 350,000 cards.
Related: Sophisticated PoS Malware “ModPOS” Targets US Retailers