The hackers who stole confidential files about stars including Lady Gaga from an A-list power lawyer claim to have sold all their “dirty laundry” on President Donald Trump to a secret buyer, and now they’re demanding at least $1 million for details on Madonna.

Hacking group REvil cyberattacked top entertainment attorney Allen Grubman’s NYC law firm and stole 756 gigabytes of documents on stars including Bruce Springsteen, Mariah Carey and U2. They doubled their ransom demand to $42 million last week after Grubman refused to pay, stating the FBI considered the hack “an act of terrorism.”

The hackers upped the ante by posting on the dark Web, “The next person we’ll be publishing is Donald Trump … We found a ton of dirty laundry.” It was not clear why the hackers connected Grubman to Trump, who has never been a client of the lawyer’s firm.

Then on Monday, REvil revealed the Trump documents were off the market, stating, “Interested people contacted us and agreed to buy all the data about the US president …We are pleased with the deal and keep our word.” They added, “We are preparing to auction Madonna data … The buyer has the right to do whatever he sees fit with the data.”

It is not known what was in the alleged Trump trove, but sources who viewed a sample on the hackers’ site said it related to snarky mentions of Trump in e-mails from Grubman’s clientele.

Brett Callow, from cybersecurity firm Emsisoft, told Page Six, “What information REvil had on Trump we may likely never know. But they were almost certainly bluffing about it being ‘presidency-ending material.’ But let’s assume this is being treated as a terrorist matter, perhaps because of Trump, so the law firm was prevented from paying the ransom or negotiating.

“The hackers were also prevented from making any money, so they went to Plan B, removing Trump from the deal and instead auctioning off the celebs’ information separately.”