ATF investigating ‘major’ cyber incident after ransomware group claim

The ATF is investigating a cybersecurity intrusion designated a “major incident” after the ransomware group Qilin claimed on its dark-web leak site to have compromised an ATF system; ATF says the affected system is separate from its primary network, found no indication of spread or operational disruption, and has not confirmed whether ransomware or data theft occurred. The designation triggers federal reporting and is notable because ATF systems support sensitive law enforcement and firearms-tracing functions, while Qilin is a prolific ransomware-as-a-service group known to exfiltrate and publish stolen data.