(Reuters) - Supermarket chain Supervalu Inc (N:SVU) reported on Monday a second attack against its payment systems barely two months after it said it was investigating a potential data breach.
The company said it found malicious software on a part of its network that might have affected payment cards used at four of its Cub Foods franchise stores in Hastings, Shakopee, Roseville and White Bear Lake, Minnesota.
The company said an intruder installed different malware on some parts of its computer network in late August or early September at some of its retail, food and associated stand-alone liquor stores.
The retailer, which operates 3,320 outlets in the United States, said this security breach was separate from the one it reported on Aug. 14.
Supervalu said the malware could have recorded account numbers, payment card expiration dates and cardholder names from cards used at the four Cub Foods stores between Aug. 27 and Sep. 21. These stores had yet to implement its protective technology.
The supermarket operator believed the malware had not succeeded in capturing data from payment cards used at any of its other stores, where it had implemented protective technology.
The attacks are not expected to have an adverse impact on its financial results or position, the company said.
Supervalu also said it notified federal law enforcement authorities and is cooperating in the investigation of the intrusion. It also notified the major payment card brands.
Cyber attacks at retailers and corporations have been growing as cyber criminals use increasingly sophisticated attacks to hack into networks and steal valuable data.
Home improvement chain Home Depot Inc (N:HD) said earlier this month that about 56 million payment cards were likely compromised in a cyber attack at its stores.
Home Depot said criminals used unique, custom-built software that had not been seen in previous attacks and was designed to evade detection.
Restaurant chain Jimmy John's also said last week there was a potential security breach involving customer credit and debit card data at 216 of its stores and franchised locations.
Supervalu shares were down about 1.8 percent in extended trading on Monday.
(Reporting by Ramkumar Iyer in Bangalore. Editing by Andre Grenon)