NSA Defies Pentagon Blacklist to Deploy Anthropic's Mythos AI in Shadow Cyber Ops

The National Security Agency has quietly tapped Anthropic's Mythos Preview, its most potent AI yet, even as the Pentagon brands the company a supply chain threat. Two sources confirmed to Axios the NSA's use of the model. One added it's spreading wider inside the department. Urgent cyber demands trump official bans.

Mythos isn't public. Anthropic limits it to about 40 organizations, citing extreme offensive cyber powers. The firm disclosed just 12. NSA ranks among the hidden users. Others scan their networks for flaws. UK counterparts grabbed access via their AI Security Institute.

But here's the twist. The Defense Department, NSA's overseer, moved in February to sever ties. It demanded Anthropic open Claude for "all lawful purposes." The company held firm: no mass domestic surveillance, no fully autonomous weapons. Tensions boiled into a supply chain risk label on March 3. That bars contractors from Anthropic tech in military work. Litigation drags on. DoD argues in court the tools endanger security -- while expanding internal reliance.

Anthropic's stand echoes earlier contracts. A July 2025 deal put Claude on classified networks first. Renegotiations collapsed. President Trump ordered a six-month phase-out February 27. Secretary Pete Hegseth called it a national security risk. Yet Claude lingers in systems, including Iran ops per Reuters.

Mythos: Zero-Day Hunter Extraordinaire

What makes Mythos irresistible? Raw cyber muscle. Anthropic's tests showed it spotting and exploiting zero-days in every major OS and browser. Thousands found. A 27-year-old OpenBSD bug. 16-year-old FFmpeg flaw. Exploits succeed over 80% first try. Engineers sans security training prompt it overnight -- wake to working code. From Anthropic's red team report, it beats prior models like Claude Opus 4.6, which flopped at exploits.

Defensive gold. Or offensive nightmare. Anthropic warns of dual-use dangers, hence the cap. Treasury, CISA, banks queue up. NSA likely probes its own nets, per The Verge sources. DoD officials gripe Anthropic can't be trusted in crises. Others push access. An administration source told Axios: "There's progress with the White House. There's not progress with [the Department of] War."

CEO Dario Amodei met White House chief Susie Wiles and Treasury's Scott Bessent April 17. Productive talks on Mythos in government, security practices. Focus shifts to non-DoD agencies like Energy. Civilian needs bypass the feud.

Fractured Lines in AI Arms Race

Bureaucratic schizophrenia. DoD litigates risks while NSA deploys. OpenAI swoops in post-ban, revising deals to block surveillance. Steve Bannon praises Anthropic's refusal. Courts loom: Anthropic sued over the label, claiming First and Fifth Amendment violations. First U.S. firm hit this way.

Implications ripple. Contractors scramble. Vendors purge Claude? Phase-out allows six months. But Mythos pulls insiders back. National security trumps policy. Cyber edges too sharp to sheath.

And so the rift widens. Pentagon pushes total access. Anthropic draws ethics lines. NSA votes with actions. In the AI cold war, capabilities dictate. Rules bend. Or break.