Anthropic: Houthi-linked users tried to build advanced missiles

Anthropic reported its safety team identified and blocked accounts in Houthi-controlled northern Yemen that attempted to use the Claude AI to design advanced missiles and other weapons. The company found evidence that actors conducted a guided-rocket test that failed and then returned to the chatbot to ask why it had failed.

Anthropic released a report on Thursday describing activity detected between December and August and identified a cell pursuing three weapons programs. The accounts used Claude Code to generate guidance, navigation and control software. Anthropic blocked the users after detecting that activity and reported the actors did not field an operational device.

The report says the group worked on a multi-variant missile that can accept different warheads and guidance systems, a hypersonic gliding variant, and a warhead that would use mobile phone hardware to maneuver during flight. Before the accounts were suspended, Anthropic found evidence the actors had built an offline simulation toolkit that did not rely on cloud platforms.

Anthropic shared its findings with private and public partners. The company has published similar disclosures twice since March 2025 about misuse of its AI platforms, covering episodes that included propaganda and research into biological threats.

Trevor Ball, a weapons analyst at Armament Research Services, noted the Houthis may be investigating hypersonics but lack the industrial base to produce them and pointed out U.S. hypersonic programs remain in testing. He added the group already operates Iranian-made anti-ship missiles with mid-course guidance and may be trying to develop local versions to reduce dependence on external suppliers.

Hazam al-Assad, a Houthi political official, rejected the suggestion the group would rely on open-source tools and asserted its forces “have modern, diverse and developed production capabilities and technology” built during the conflict with the Saudi-led coalition. He characterized the weapons as used for self-defense.

The Houthis have used drones, cruise and ballistic missiles and other munitions in recent years. They have claimed responsibility for attacks on Saudi oil infrastructure and tankers in the Red Sea and have seized territory along the Red Sea coast and the Bab al-Mandeb Strait. Researchers have observed the group developing technical skill in weapons modification and information operations.

Anthropic did not identify the specific accounts or name individuals in its report. The company described the findings as part of a broader pattern of actors seeking to misuse AI tools for military and malicious purposes and stated monitoring and defensive measures remain a priority for its security teams.