ATF declares ‘major incident’ as ransomware gang claims hack

The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives, or ATF, says a cyberattack on one of its systems has been declared a “major incident,” a formal, legally defined classification that prompts a formal notification to lawmakers in Congress.

ATF said in a statement that it’s responding to the cyberattack on a stand-alone system that’s separate from the bureau’s network. An ATF spokesperson told reporters that the targeted computer system contained information such as the “targets of ATF investigations.”