Lulz Security, which was allegedly behind the attack on Arizona police website, CIA website, US Senate website, SonyPictures and many more government sites around the globe, claimed the responsibility for the attack through their Twitter account.
"We have joy we have fun, we have messed up Murdoch's Sun," LulzSec tweeted.
The fake news about Murdoch's death came a day before he is to appear in parliament over the phone hacking scandal, that resulted in shutting down the 168-year-old tabloid 'News of The World' and the resignation and arrest of its then editor in chief and former CEO Rebekah Brooks.
Users who entered The Sun's website was greeted with the story with a headline "Media moguls body discovered".
The story continued: "Murdoch, aged 80, has said to have ingested a large quantity of palladium before stumbling into his famous topiary garden late last night, passing out in the early hours of the morning."
LulzSec also claimed that they had hacked other websites run by News International. Media reported that error message was showed while trying to login to the website of The Times, a News International paper, as well as News International's home page.
The latest attack came a few days after LulzSec announced its retirement form hacking. The hacker group told that members were bored of hacking. "It's time to say bon voyage. Our planned 50-day cruise has expired, and we must now sail into the distance," LulzSec said in a post.
Meanwhile, News International said that it was looking into the matter. "We are aware and our technical teams are working on it," said News Corp. spokeswoman Daisy Dunlop.