The military, including Cyber Command, has taken action against some ransomware groups after recent attacks on American companies, according to the nation’s top cyberdefense executive.

Agencies have stepped up their efforts against ransomware groups after recent attacks on Colonial Pipeline and meat processor JBS, said Gen. Paul Nakasone, the head of Cyber Command and the director of the National Security Agency, according to the New York Times. Nakasone’s acknowledgment of Cyber Command’s effort is the first public disclosure of offensive cybersecurity operations against ransomware groups.