“The current system is broken, retailers big and small experience a breach and months go by without any notice to credit unions of which cards are compromised, which results in a spike in fraud losses, and once again local credit unions are left holding the bag,” Adams said. “Again, we call on lawmakers and regulators to use their full authority to ensure both retailers and card network companies are doing their part to protect customer's information instead of leaving credit unions to continually shoulder the burden.”

Cybersecurity expert Brian Krebs first reported the breach in January. According to Wendy's, malware was discovered on some of the franchise restaurants' POS systems. In mid-May, the company announced in its first quarter financial statement that the fraud only affected 5% of stores, fewer than 300 locations.

However, a number of sources in the fraud and banking community told Krebs there was no way the Wendy's breach only affected 5% of stores, given the volume of fraud the financial institutions traced back to Wendy's customers.

The Wendy's chain includes about 6,500 franchise and company operated restaurants in the United States, 28 other countries and U.S. territories worldwide. Most of the U.S.-operated stores are franchises.