The catastrophic hack of at least thousands of FBI officials’ personal data, including their addresses, phone numbers, and even their spouses, includes members of the FBI’s secretive hacking team, potentially revealing who exactly is in that unit, 404 Media has found.

The findings further highlight how sensitive the stolen data is, and how valuable it may be to criminals or to foreign intelligence agencies. There is very little public information about the FBI’s hacking unit, including the operations it conducts, the tools it uses, or which agents are part of it.

FBIjobs.gov offline on Wednesday as ShinyHunters group claims to have accessed records of agents and applicants

The FBI is investigating an apparent breach of its jobs website as a criminal hacking group claimed to have accessed “very sensitive data” on nearly all agents and job applicants.

“The FBI is aware of claims regarding unauthorized activity affecting FBIjobs.gov and is currently investigating,” the bureau said in a statement. The website, the main portal for prospective employees to learn about the FBI and initiate the application process, remained offline Wednesday morning.