Monday kicks off with news about new hacking attacks against the official website of national carrier Malaysia Airlines (MAS) and Russia-based online dating service Topface. A group calling itself "Official Cyber Caliphate" said it hacked on Monday the website of Malaysia Airlines, but the airline said its data servers remained intact and passenger bookings were not affected.

The website, www.malaysiaairlines.com, showed a photograph of a lizard in a top hat, the name of the hacker group Lizard Squad, surrounded by the messages '404 - Plane Not Found' and 'Hacked by Lizard Squad - Official Cyber Caliphate'.

MAS said the website was not hacked, but that users were redirected to a hacker website. It said the official site would be back up within 22 hours.

Earlier this month, Twitter and YouTube accounts of the U.S. Central Command were compromised by messages supporting Islamic State in a hacking attack the Pentagon dismissed as a prank.

Last year, the website of Sony’s pictures unit was hacked, and researchers began pointing fingers at everyone from an ex-Sony employee to Russian criminals to the Lizard Squad.

Seperately, user names and e-mail addresses of 20 million visitors to Topface , a Russia-based online dating service have been hacked and offered for sale on a website, according to fraud-detection software-maker Easy Solutions.

In a statement, Topface Chief Executive Officer Dmitry Filatov said while he has no proof of the breach, the company is investigating.

But according to researchers at Easy Solutions, hackers can use stolen credentials to try to access bank accounts, health records or other more sensitive data.

Topface says says it has more than 90 million registered users.