Predictably, hackers struck the Winter Olympics even before it got into full swing–something that experts feared might happen, as reported on Friday. The cyberattack occurred during the opening ceremony. According to reports, the intent was specifically to create disruption. Interestingly, Olympic officials have chosen not to reveal (yet) who is behind the attack.

Malware dubbed ‘Olympic Destroyer’ is believed to have been used in the strike that affected the games’ internet and television services, designed to knock out services and data . “The official Pyeongchang 2018 website went down hours before the opening ceremony, making it impossible for customers to print tickets or look up the events schedule. It took 12 hours for the site to get back online” reports Vox.

Meanwhile, WiFi went down at the Olympic stadium and televisions in the press center stopped working, according to the Guardian. In addition, Reuters reports, “Drones that were intended to be used in the program failed to deploy, prompting organizers to insert pre-recorded footage of the drones in global telecasts.”

Those who have analyzed the cyberattack have not seen any evidence of data being stolen.

Read the full story at Vox.