Ransomware - which effectively holds files and networks hostage unless a payment is made - has steadily climbed to the top of America’s security agenda as the criminals behind it become increasingly well-resourced.

Speaking via a webcast, Mayorkas said that ransomware was “a particularly egregious type of malicious cyber activity” and listed it as the first of several top priorities that his department would tackle in the online sphere.

Many ransomware operators work out of jurisdictions with a lax attitude to cybercrime, and Mayorkas said he would seek to hold accountable “governments that do not use the full extent of their authority to stop the culprits.”

Mayorkas said the government would seek to disrupt not just those that launched ransomware operations but also “the marketplaces that enable them.”

Mayorkas did not say so explicitly, but a DHS official said the reference was to underground forums that help cybercriminals franchise out their malicious campaigns.

Earlier in his address, Mayorkas laid out an ambitious role for the Cybersecurity and Infrastructure Security Agency (CISA), which is DHS’ cyber arm. He said the agency would “quarterback” the U.S. government’s digital defenses and serve as a “trusted interlocutor” between business executives and public servants.

“It is clearly best positioned to be the tip of the spear and the front door for the U.S. government’s engagement with industry on cybersecurity,” he said.