POLSON — Last week’s cyber-attack on regional grocery store chains has been blocked and all card transactions have been resumed, said URM Stores CEO Ray Sprinkle in a statement on Monday.

Cards used through a separate “stand-beside” or a dial-up system between Nov. 25 and Dec. 2 were not affected, Sprinkle said.

Customers that used their cards during the attack should continue to monitor their accounts for suspicious activity and report any unauthorized purchases to the financial institution that issued their card. Most credit card companies have zero liability policies that guarantee that cardholders will not be responsible for any fraudulent charges, Sprinkle said in the release.

Sprinkle said the company has implemented “enhanced security measures designed to block the cyber-attack” and they plan to use this as a learning experience moving forward. Efforts will now focus on figuring out which stores were targeted and how long they were under attack. Once they have identified specific stores, URM plans to alert card companies who might have issued at-risk cards so that card companies can in turn take action to protect their customers.

Customers of Polson Super One were using cards to pay for groceries Sunday afternoon, after signs stating ‘use at your own risk’ had been removed over the weekend. In an electronic correspondence store owner Greg Hertz said the situation has been contained.

Information concerning the cyber-attack can be found on the URM Stores website.