Supervalu looks like the latest data breach victim

In addition to servicing its own stores, which include the Albertsons, Acme Markets, Jewel-Osco, Shaw's and Star Markets brands, the supermarket chain also provides tech support to Cub Foods, Hornbacher's and Farm Fresh, in roughly two dozen states.

Supervalu called the hack a "criminal intrusion" that might have netted account numbers, expiration dates and cardholder names from customers who used plastic cards at stores.

The hackers might have inserted malware into the company's point-of-sale network. That system includes the cash register and terminals that handle credit and debit card transactions.

The company says the incident might have affected about 200 stores, while people familiar with the situation have placed the figure at up to 1,000 locations.

Supervalu recently sold the other stores affected.

The company has not determined that any cardholder data “was in fact stolen by the intruder, and it has no evidence of any misuse of any such data, but is making this announcement out of an abundance of caution," Supervalu said.

An investigation is ongoing.