Malaysia Airlines' website has been hacked by a group proclaiming support for the so-called Islamic State.
A message saying "404 - Plane Not Found" and that it was "Hacked by Cyber Caliphate" appeared on the airline's site in the early hours of Monday.
The browser tab for the site also said "ISIS will prevail" before it was changed to "Lizard Squad - Official Cyber Caliphate".
Malaysia Airlines confirmed the hack, claiming its system had been "compromised" but reassured customers that no personal data had been stolen in the attack.
The hacking comes weeks after the US Central Command's Twitter and YouTube accounts were apparently hacked by Islamic State supporters.