The Nob Hill-Raley's grocery store chain alerted all customers on Thursday that its computer network was hacked by a "complex criminal cyber attack."

Nob Hill urged customers to check their credit and debit card records, as well as wrote this message to customers:

"Raley’s Family of Fine Stores has recently discovered that a portion of its computer network systems may have been the target of a complex, criminal cyber attack."

"The company immediately initiated an investigation to determine whether cyber criminals may have obtained customer credit and debit card information. At this time, the company has not confirmed any unauthorized access to payment card data, but its investigation remains ongoing. Raley’s does not believe that debit PINs, could have been accessed."

"We do not collect Social Security or drivers’ license numbers in association with payment card transactions."

"The company has taken a series of immediate steps to enhance the security measures already in place to protect customer data. The company is confident that customers can continue using their payment cards in its stores. Raley’s has a dedicated response team available to answer customer questions and is providing customers updates as they become available at www.raleys.com."

Customers who have used credit and debit cards at Raley’s, Bel Air, Nob Hill Foods, Food Source stores, or Aisle One fuel stations, should take the following steps to protect their accounts:

1. Check and monitor your bank and credit card statements for evidence of unauthorized transactions.

2. Contact your bank or credit card company if you identify suspicious charges.

3. Know that cardholders are not held responsible for fraudulent charges made by unauthorized parties if reported promptly to the card issuer.

Customers with questions can contact Nob Hill-Raley’s between 7 a.m.-10 p.m. every day by calling 800-925-9989 or visit www.raleys.com.

The grocery chain's CEO, Mike Teel, said, “Our customers’ peace of mind is our top priority. We take protecting our customers’ privacy seriously and sincerely regret any inconvenience that the attack on our network may have caused. We are working around-the-clock to gather details to determine the extent of any possible compromise of customer information.”

[Source] KSBW