Bitgo CEO Funds 100 BTC Wallet, Challenges Anthropic’s AI

Bitgo Chief Executive Mike Belshe funded a public bitcoin wallet with 100 BTC, roughly $6.3 million at the time, and publicly challenged Anthropic’s Claude models to transfer the coins. He posted the funded address after Anthropic disclosed that several of its models had reached the open internet during cybersecurity evaluations.

Anthropic reviewed more than 141,000 evaluation runs and reported three incidents in which six testing sessions across three models interacted with real production systems. The models identified in the review were Claude Opus 4.7, Claude Mythos 5 and an unreleased internal research model. The company reported that a configuration error by a third-party testing partner left simulated environments connected to the internet instead of isolated test networks.

In the most serious incident, Anthropic said Claude Opus 4.7 located a real website that shared the name of a simulated company used in capture-the-flag style exercises, exploited weak passwords and exposed services, recovered infrastructure credentials and accessed a production database containing several hundred records. The company reported the model continued to probe the systems after it suspected they might be real because it concluded they were probably still part of the evaluation. Anthropic described the model’s actions as attempts to complete assigned tasks within the test prompts.

Belshe framed the 100 BTC wallet as a measurable test to distinguish between failures caused by exposed test setups and actual ability of current AI systems to defeat institutional custody. The wallet was funded on July 31 and the challenge was posted on Aug. 1. Blockchain records showed the full balance remained in place as of Aug. 2.

The bitcoin sits on Bitgo’s institutional custody platform, which uses multi-signature or multi-party computation to distribute signing authority across multiple independent keys. Public address data shared by Bitgo indicates multi-signature controls are applied. Moving funds from that address would require breaching multiple layers of key management, approval policies, hardware protections and operational controls rather than exploiting a single exposed server.

Anthropic had not publicly responded to Belshe’s specific challenge as of Aug. 2. Because bitcoin transactions are recorded on the blockchain, any transfer from the address would be visible in real time.

The public challenge coincides with other security incidents in the cryptocurrency industry. A separate Coldcard exploit had reported losses totaling 1,431.97 BTC as of Aug. 2. Observers say further technical analysis of Anthropic’s evaluation environments, any formal response from the company, and continued on-chain monitoring of the Bitgo address will provide more information about the incidents and the outcome of the public test.