The FBI has classified a breach of its jobs portal as a “major” cybersecurity incident after a criminal group claimed it stole sensitive information, including Social Security numbers and birth dates. The bureau made the determination Sept. 22 and notified Congress three days later, according to a notice sent to lawmakers. The designation applies to incidents likely to cause demonstrable harm to national security, economic well-being or public safety, including exposure of sensitive personal information. The cybercrime group ShinyHunters claimed responsibility last week and said it had obtained data on “nearly all” FBI employees. The FBI’s major-incident finding adds weight to concerns about the breach but does not, by itself, verify the group’s claim about how many people were affected. FBI spokesperson Benjamin Williamson said the bureau sent its first agency-wide email about the breach on Sept. 22, less than 12 hours after public reporting surfaced. He did not answer questions about whether that email told staff the bureau had already classified the incident as major. Three congressional aides familiar with the notice confirmed receiving the same correspondence on Sept. 25. The information available publicly did not specify how many current or former employees, applicants or others may have had their data exposed, or what steps the FBI is taking to protect those affected.