Kash Patel is facing a major security breach at the FBI after hackers claimed to have stolen personal data on every employee and job applicant at the bureau.

ShinyHunters, a notorious hacking gang, said it obtained FBI agents' names, home addresses, phone numbers and dates of birth, and even details on their spouses. 

The gang also defaced the FBI's jobs website on Tuesday, writing: 'This site has been seized by ShinyHunters.' The message mocked the seizure notices the bureau plasters on criminal sites it takes down. 

They then trolled Donald Trump, ending the message with the president's trademark Truth Social sign-off: 'Thank you for your attention to this matter.'  

One of the hackers issued a menacing threat to the Trump administration in an interview with 404 Media, which first reported the alleged breach. 

'What we plan to do is not something I'd call extortion, maybe coercion,' the hacker said of their plans, adding that it was 'not financially motivated.' 

The gang typically steals data and then demands ransom, threatening to dump more files if victims refuse to pay. 

The FBI told the Daily Mail in a statement: 'The FBI is aware of claims regarding unauthorized activity affecting FBIjobs.gov and is currently investigating.' 

A sample of 5,000 records shared by the gang contained purported addresses, phone numbers and dates of birth, and in some cases details on spouses. 

Some of the leaked phone numbers matched people with the same names in open-source intelligence databases, and several were linked to Justice Department personnel, according to checks by 404 Media.  

The message left on the jobs site went further, claiming the gang had personal and health information on current and former FBI employees, plus every applicant. 

'We have a lot more than we claim here,' it added.

The site was later knocked offline, with a notice warning that the Special Agent Applicant Portal was 'currently unavailable.'

The FBI has previously warned that ShinyHunters-linked criminals use stolen personal information to harass victims and their families. 

The representative said the gang struck on Monday night by exploiting a previously unknown flaw, called a zero-day, in Oracle's PeopleSoft software. 

The hackers then claimed to have accessed Amazon's AWS GovCloud servers, a cloud service built to hold sensitive US government data, and stolen between two and three terabytes of files. 

The Daily Mail has contacted Oracle and Amazon for comment. 

The alleged breach comes as Patel, 46, faces mounting scrutiny over controversies at the bureau since he was sworn in as FBI director in February last year. 

Patel last week faced heated questioning at a Senate Judiciary Committee hearing over changes to FBI hiring standards involving prostitution and bestiality. 

Patel defended the changes, saying they were meant to let victims of those acts apply for FBI jobs without being automatically disqualified.

In April, Patel filed a $250 million defamation lawsuit against The Atlantic over an article alleging mismanagement at the agency and excessive drinking, claims he denies. 

He has also faced scrutiny over his use of the bureau's $60 million jet, including a trip to see his girlfriend, country singer Alexis Wilkins, perform at a Penn State wrestling event last year. 

Patel has insisted he is 'entitled to a personal life just like my other agency counterparts with their partners.'