A Turkish hacking group defaced the homepage of Sandy Springs-based UPS Sunday, declaring it "World Hackers Day."

The group, TurkGuvenligi, replaced the company's webpage with its name over the image of a red dragon and directed visitors its its Twitter feed. The group's Twitter site, which features tweets in Turkey and broken English, made no apparent reference to the UPS hack.

UPS spokeswoman Laurie Mallis said customer data and company information were not affected by the attack, which she said was related to the company UPS uses to register its domain name.

"It's my understanding there is a fix in place," she said, although the UPS site still was down Sunday evening.

Zone-H.org, a site that archives hacked webpages, reports that TurkGuvenligi is behind similar attacks Sunday on the webpages of Vodofone, National Geographic, computer company Acer and British technology site The Register, among others.