The Malaysia Airlines website has been commandeered by hackers who referenced Islamic State and claimed to be from the "Lizard Squad", a group known for previous denial-of-service attacks.

The website's front page, malaysiaairlines.com, was replaced with an image of a tuxedo-wearing lizard, and read "Hacked by LIZARD SQUAD - OFFICIAL CYBER CALIPHATE".

A professional-sounding rap, apparently released on Christmas Day, played automatically in the background when the website was visited.

It also carried the headline "404 - Plane Not Found", an apparent reference to the airlines' puzzling loss of flight MH370 last year with 239 people aboard.

Media reports said versions of the takeover in some regions included the wording "ISIS will prevail".

The airline did not immediately respond to a request for comment.

According to a post by the main Lizard Squad Twitter account, @LizardMafia, the Malaysia Airlines website was defaced at about 1.14pm NZ time. More than six hours later, at 7.08pm, it remained defaced.

In Malaysia, the attack began at about 8.14am local time.

Soon after the attack, the Lizard Squad Twitter account said the group planned to shortly release "loot" — i.e. stolen data — found on the server hosting the Malaysia Airlines website. As part of a teaser, it posted a screenshot that appeared to show Malaysia Airline customer travel itineraries.

The Lizard Squad is a group of hackers that has caused havoc in the online world before, taking credit for attacks that took down the Sony PlayStation Network and Microsoft's Xbox Live network last month.

Islamic State, an extremist Sunni Muslim group, has seized large swathes of Syria and Iraq, where it has declared an Islamic "caliphate".

It has drawn thousands of fighters from across the globe to its anti-Western cause, and shocked the world with its video-taped executions of journalists and other foreigners it has captured, the most recent being a Japanese security contractor it claimed to have beheaded.

A second Japanese captive being held by the militants has also been threatened with execution.

IS, which uses social media in recruiting and spreading its message, is believed to harbour ambitions of launching a cyber war against the West.

It is unclear why Malaysia Airlines was targeted.

But concern has been rising in Malaysia after scores of its citizens were lured to the IS cause in the Middle East. Malaysian authorities last week said they have detained 120 people suspected of having IS sympathies or planning to travel to Syria.

Listen: The rap (Warning: explicit language) that streams on the defaced site

AFP, Reuters and Fairfax Media