The hackers managed to gain access to a server containing personal data of customers. This includes name, address, telephone number and e-mail address.
Gamemania emphasizes that no passwords or payment details have come into the hands of the hackers, but the company is not saying how much customer data was stolen.
The data breach has been reported to the Dutch Data Protection Authority and its Belgian counterpart.
Gamemania does not say whether they have paid any amount to get their hands on encrypted systems again. The company has engaged experts to look at how the hackers got in and fix the problem. The webshop and the physical stores in Belgium are open as usual, according to Gamemania.
Gamemania warns its customers to be alert to suspicious emails asking to change a password. The chain has 21 stores in Belgium and 36 stores in the Netherlands.