Website of a high-profile law firm hacked, clients include celebrities like Lady Gaga, Priyanka Chopra

The official website of an A-list law firm, which has several celebrity clients like Lady Gaga, Robert DeNiro, Elton John and others, has been hacked.

The website for Grubman Shire Meiselas & Sacks is down and hackers have claimed to have access to 756 gigabytes of data including contracts and personal emails.

A screenshot allegedly of a contract of popstar Madonna has been released and the hackers are now demanding payment.

The New York-based firm states it has notified its clients and is working with cyber-security experts. It is not known yet how much the hackers are demanding or if the law firm is negotiating with them.

In a statement released to the press, the firm states, “We can confirm that we've been victimized by a cyber-attack. We have notified our clients and our staff. We have hired the world's experts who specialise in this area, and we are working around the clock to address these matters."

The company's website is displaying just a logo but historic records of the site show a client list of more than 200 high profile people and companies.

Some of the world’s most prominent celebrities are handled by the law firm which includes musicians Sir Elton John, Barbra Streisand, Barry Manilow, Rod Stewart, Lady Gaga, Lil Nas X, The Weeknd, Madonna, U2 and Drake. Priyanka Chopra, Robert De Niro, Sofia Vergara, and Mike Tyson are also part of the film’s clientele.

he hackers have been identified as REvil or Sodinokibi who previously attacked foreign exchange company Travelex in January. That case was too, was ransomware.

Ransomware is typically a malicious type of software that encrypts data until a ransom is paid, usually in untraceable crypto-currency Bitcoin. It is one of the biggest and common cybersecurity threats these days.

Hackers reportedly have posted images online of a contract for Madonna's World Tour 2019-20 complete with signatures from an employee and concert company Live Nation.

Another image shows a screenshot of the stolen data directory with folders named under certain clients including Bruce Springsteen.

Cybersecurity experts state that a sample of stolen data is often shared to prove that a hack has taken place which puts pressure on the victim to pay up a ransom.