Claude Mythos AI Autonomously Executes Full Cyber Kill Chain Without Human Guidance
Booz Allen's benchmark found Anthropic's Claude Mythos was the only tested model to autonomously complete a full cyber kill chain to domain administrator control.
Booz Allen assessed 18 US and Chinese models as autonomous attackers against a production-grade enterprise network, measuring actions via network and host telemetry. Claude Mythos scored 80 on the Cyber Weapon Index (74 vulnerability research, 86 kill-chain attainment), moving from a stolen employee credential to administrator-level control in every credentialed attempt. Only frontier Anthropic models identified the previously unseen flaw in compiled software, and only Claude Mythos exploited it; the report notes a harness paired with Claude Sonnet could rival Claude Mythos. The result is a controlled benchmark, not evidence of a real-world campaign or victim breach.
AI labs have a data trust problem that their policies haven't solved
Nvidia, Palantir, and Booz Allen restrict Anthropic's Fable over data-retention distrust, exposing gaps in AI labs' customer data policies.
Nvidia limits Anthropic's Fable to non-sensitive work and runs its own Nemotron models for internal tasks, while Palantir blocks Fable deployment until Anthropic grants irrevocable zero-data-retention guarantees, and Booz Allen bans it for proprietary cybersecurity work. John Schulman and researcher Sarah Hooker explain that labs can still extract customer IP from metadata, user traces, and synthetic data even under zero data retention. The trust crisis crystallized around Tristan Buckmaster's accusation that OpenAI's Codex absorbed his Navier-Stokes drafts, though OpenAI later stated his prompts could not have influenced its model.
New CISO appointments 2026
Companies including Mistral AI, Trellix, Marriott, and ANZ appointed new CISOs in July-September 2026 amid high security-leadership turnover.
CSO Online's rolling column tracks senior security appointments, noting many companies are hiring a CSO/CISO for the first time. Notable moves include Thomas Coudray leaving Ledger to become Mistral AI's CISO, David Soto joining Trellix from Amazon, and Daniel Dubowski becoming Marriott International's SVP and CISO. Other appointments span ANZ, Gigamon, Axonius, Tricentis, Remitly, Allied Universal, and the State of California.
HiddenLayer nabs $100M as enterprises rush to secure their AI deployments
AI security startup HiddenLayer raised a $100 million Series B led by Delta-v Capital as enterprise spending on securing AI deployments accelerates.
HiddenLayer, which protects AI models, agents, and workflows from adversarial attacks, vulnerabilities, and code injections, raised a $100 million Series B led by Delta-v Capital with participation from Ten Eleven Ventures, Morgan Stanley, Microsoft's M12, and Booz Allen Hamilton. The company says annual recurring revenue grew more than 10x to the tens of millions of dollars, with customers including the Department of Defense, the intelligence community, and a frontier model provider with over 700 million weekly users. Gartner estimates enterprise spending on AI security products will reach $2.83 billion in 2026, up 83% from 2025, and nearly $4.78 billion next year.