The hacker gained access to the database by posing as a guest on the brands website while checking out something.
The hacker got access to addresses, phone numbers and last four digits of a credit or debit card of customers according to Hanesbrands Inc.
The breach happened in the last month of June according to Hanesbrands spokesman Matt Hall and does not affect the retail stores of the brand.
The brand had themselves been contacted by the hacker to inform them of the breach.