Update as of 1:00 a.m. EST: Malaysia Airlines confirmed Monday that its website had been “compromised” but added that the issue has been resolved and that “the system is expected to be fully recovered within 22 hours.” The incident has been reported to CyberSecurity Malaysia and the Ministry of Transport, the airline wrote in a statement posted on its Facebook page.  

“Malaysia Airlines assures customers and clients that its website was not hacked and this temporary glitch does not affect their bookings and that user data remains secured,” the airline said in the statement.

However, the Lizard Squad, which has claimed responsibility for the hack, disputed this claim in a post on Twitter.

Original Story:

A group aligned with the Islamic State group early Monday hacked the website of Malaysia Airlines, still reeling from last year's  loss of two aircraft that left more than 500 people dead or missing. The Wall Street Journal reported the Cyber Caliphate claimed responsibility for leaving the message "ISIS Will Prevail" on the airline's webpage, www.malaysiaairlines.com.

The hackers also put up the message "404 -- Plane Not Found, Hacked by Cyber Caliphate" in white letters in the middle of the homepage, an apparent reference to Malaysia Airlines Flight MH370, which disappeared en route to Beijing from Kuala Lumpur, Malaysia, last March. The hackers also replaced the background music with a rap song, CNBC reported.

At 2:30 a.m. GMT Monday (9:30 p.m. EST Sunday), the site's background turned black and a picture of a lizard in a top hat and monocle, a pipe in its mouth, appeared -- the same image as that used on the Twitter page of the Lizard Squad, best known for hacking gaming sites, CNBC said.

The hack interfered with website operations, and Malaysia Airlines apologized to customers for the inconvenience. No reason was given for the hack.

The airline had a tough year in 2014. First MH370 disappeared somewhere over the Indian Ocean March 8 after the pilot apparently strayed from the flight path. The Boeing 777-200ER was carrying a crew of 12 and 227 passengers from 15 nations. No trace of the plane has yet been found despite a massive search.

Flight MH17, a Boeing 777-200ER carrying 283 passengers and 15 crew, was shot down over Ukraine July 17 by Russian-backed Ukrainian separatists. The plane was en route from Amsterdam to Kuala Lumpur. The Dutch government is leading the investigation, with the final report due in August. Russia has claimed the Ukrainian government was responsible for the incident, but evidence indicated separatists fired the fatal missile, according to a preliminary report.