KFOR TV is reporting that fast-food chain Sonic Drive-In is investigating a possible data breach that may have impacted millions of credit and debit cards used at its drive-ins.  Officials with Sonic Drive-In, a fast food chain with nearly 3,600 locations, said this week they had been notified of “unusual activity” regarding credit and debit cards used at Sonic.

“The ongoing breach may have led to a fire sale on millions of stolen credit and debit card accounts that are now being peddled in shadowy underground cybercrime stores,” according to KrebsOnSecurity, which first reported the possible breach.

Read the full KFOR story by clicking here.