The company joins a number of others that have declared data breaches or other data security incidents this year. Panera left millions of its customers' records exposed on its site while Orbitz announced a breach that exposed some 880,000 credit cards. An Under Armour security breach exposed 150 million MyFitnessPal accounts, hackers stole info on 5 million payment cards from Saks Fifth Avenue and Lord & Taylor and a tech firm called [24]7.ai suffered a breach that may have exposed the customer data of its partners, which include Sears, Delta and Best Buy.

Adidas says it's working with data security firms and law enforcement as it investigates the incident. It's also alerting any customers that might have been affected.