At the onset of one of the busiest shopping weeks of the year, customers at multiple grocery stores in the region are being asked to use cash and checks to make purchases while investigators work to fix a payment processing system compromised by a criminal cyber attack.

Local residents have reported being among those to have money stolen from their accounts.

The targeted system is run by URM Stores Inc., a Spokane-based grocery wholesaler overseeing numerous chains throughout the area, including the Super One Foods in Polson and Harvest Foods in Ronan.

On Monday, Ray Sprinkle, the CEO of URM, issued a release stating that law enforcement officials and a financial institution advised his company that they may have been the target of a cyber attack against the payment system, which processes debit and credit card transactions.

Signs posted at the registers of the Polson Super One read “we recommend you consider paying in cash or check until we finish blocking the attack.”

On Wednesday, store owner Greg Hertz said that the company aims to have the problem fixed by Monday.