A consumer alert now for people who have used their credit or debit cards at Wendy's.
The fast food chain says the malware discovered earlier this year may have affected more restaurants than originally thought.
Wendy's has been investigating reports of fraudulent charges on people's credits cards since January.
The company thinks the attack on its payment system may be considerably higher than the three hundred restaurants already affected.
Customers are encouraged to keep an eye out for any unauthorized charges on cards they may have used at a Wendy's restaurant.