Adidas has reported it was the target of a "sophisticated, criminal" cyber attack.
On 3 November, Adidas discovered the incident and immediately took website content offline.
"While we continue our thorough forensic review, we have taken down affected sites, including adidas.com, reebok.com, miCoach.com, adidas-group.com and various local eCommerce shops, in order to protect visitors to our sites," Adidas reported on its website.
When users try to access the Adidas.com website, a message appears apologising for inconveniences while also thanking users for understanding.
Some of the sportswear giant's ecommerce sites do work though, including geography-specific websites in Canada, France, Germany, Netherlands, Russia, UK and US, which are linked on the Adidas website.
Nothing is more important to us than the privacy and security of our consumers' personal data.
After investigating, no evidence was found that any consumer data was stolen, the company said.
Adidas claimed to have put in place additional data security measures since learning about the issue.
"Nothing is more important to us than the privacy and security of our consumers' personal data. We appreciate your understanding and patience during this time," Adidas added.
There was no information on who the perpetrators of the hack were, how they carried out the attack or when services would be back online.
In the past, "sophisticated" has referred to Advanced Persistent Threat (APT) attacks. Defending against APTs was one of the tasks involved in a recent EU-US joint test of cyber attack readiness.
