A group of cybercriminals is demanding a $21 million ransom from a New York-based law firm representing megastars like Lady Gaga, Madonna and Elton John, according to The New York Post. The infiltrators, which are believed to be part of a group called REvil or Sodinokibi, claim to have stolen 756 gigabytes of data from Grubman Shire Meiselas & Sacks’ computers. They also claim that the data cache includes contracts, personal correspondence, phone numbers and email addresses.

Variety says the group already attempted to share a one-gigabyte collection of documents on Mega, but the file—sharing service took down the account. They also apparently released a screenshot of Madonna’s contract. A source told the Post that the hackers got in “while everyone was focused on the coronavirus.” The firm, which is reportedly not negotiating with the group, said in a statement: