ShinyHunters told 404 Media it hacked the FBI and holds data on all employees and applicants.
The claim, reported by 404 Media, includes a sample of 5,000 alleged agents with names, home addresses, phone numbers and spouse details reviewed by journalist Joseph Cox.
The group described the compromise as affecting multiple FBI-related services, implying remote access rather than local device compromise, though no exploit details or patch status were disclosed.
The FBI said it was probing a suspected hack after the claim surfaced, according to Politico.
Verification requires confirming chain of custody for the sample, cross-checking personnel records, and identifying which recruitment or background-check system was exposed.
That verification still has to happen before national security impact can be assessed, and before any notification to affected employees and families can begin.
If validated, exposure of home addresses and spouse information would expand risk from individual agents to households, a vector previously used for tracking and intimidation of investigators.
No confirmed distribution of the full dataset has been reported, and 404 Media noted the disclosure sits behind a paywall pending further verification.
