ATF responds to 'major' cybersecurity incident after ransomware gang's claims

The ATF has confirmed a "major" cybersecurity incident after the Qilin ransomware gang listed the agency on its leak site; ATF says a standalone system containing information about investigation targets was accessed, DOJ is investigating, and connections to the affected environment were immediately blocked. The agency reports no indication the enterprise network or core services were affected, and Qilin's public claim lacks publicly released samples or details about data stolen or ransom demands.