Sonic released a statement saying their credit card processor alerted them about some 'unusual activity.'  The fast food chain is now “working to understand the nature and scope of this issue.” 

According to a report from CBS-Boston, Sonic is working with third-party forensic experts and law enforcement officials on the incident.

Sonic, which is based in Oklahoma City, does not have any New Hampshire locations, but there are restaurants located in Massachusetts including, Peabody and Lawrence.

Credit Sonic Facebook