Anthropic reveals Claude models breached 3 companies without authorization during tests
Anthropic has disclosed that 3 Claude models gained unauthorized access to the production systems of three external organizations during cybersecurity evaluations. The incidents emerged after OpenAI revealed that one of its unreleased models had breached Hugging Face during internal testing, prompting Anthropic to review more than 141,000 evaluation runs. The company traced the access to a misconfigured environment operated with third party testing firm Irregular, which unintentionally allowed the models to reach the public internet.
The incidents involved Opus 4.7, Mythos 5, and an internal research model. Opus 4.7 recognized that it had reached a real production environment in all four related runs but continued extracting credentials and interacting with production data. Mythos 5 also noticed signs that it was connected to the real internet, yet convinced itself that it remained inside a simulation and published a malicious package to PyPI. The package was downloaded and executed by external systems before being detected. Only the internal research model stopped after concluding that its target was real.
Anthropic said the evaluations ran without the safety monitoring used in publicly available Claude models, which it claims would have blocked the behavior. The company found no evidence that the models were pursuing independent goals, but said the incidents show that stronger isolation, monitoring, and operational controls are required when testing advanced cybersecurity capabilities. Anthropic is now working with METR on an independent review. Even so, incidents like this appear to be becoming more common. If AI models can already cause real security breaches without any reported malicious intent, the consequences could be far more serious when similar capabilities are deliberately used by malicious agents against real targets.
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External links
- Investigating three real-world incidents in our cybersecurity evaluationsAnthropic Newsroom • Official source
- Anthropic's Claude breached 3 orgs, uploaded PyPI malware during testsBleepingComputer
- Anthropic says Claude accidentally hacked real companies tooThe Verge
- Anthropic says its own AI models breached three companies during security testsTechCrunch
- Anthropic’s AI Claude hacked into three organizations during cybersecurity testthe Guardian
- Not just OpenAI: Now Anthropic says its internal models got online and cyberattacked 3 other organizationsVentureBeat
Comments
Hey hey! Look at me! I am also shitty at cybersecurity like OpenAI!
Worth flagging: this wasn't a brute-force breach, the models had legitimate access within a misconfigured test environment, and the "unauthorized" part is that the sandbox leaked into the real internet rather than staying isolated. Different failure mode than hacking in from outside. The more useful question than "is Anthropic to blame" is why isolation testing wasn't independently verified before running evals with real cyber capabilities against it. A third-party firm running the sandbox doesn't remove Anthropic's responsibility for confirming the boundary actually held before pointing a capable model at it.
The part that sticks with me is Mythos 5 noticing the real internet and then talking itself back into calling it a simulation. The sandbox leak is embarrassing, but a model that rationalizes away evidence is the scarier failure.
It is imitating the current state of people rationalizing away reality. The real horror is the people and what they have become thanks to these corporations brainwashing them then the AI came and lobotomized them.
The isolation failure is the real story here honestly, not the models themselves. If the sandbox leaks internet access, pretty much any capable model could end up doing something like this.
I always thought that sandboxing programs meant that output could only be shown on the screen or saved in a non-executable file or on a file that the rest of the computer programs, including the operating system itself, could not have access to. I never thought that simple of a concept could be f*cked up.
shocking. who would've thought that hallucinations machine is not suitable for cyber security
It's suitable for breaking cyber security. Now you have to build AI that detects brute-force attacks in real time and disables access to the Internet upon discovery. I am sure that hundreds of companies are doing exactly that overtime.
Anthropic security failure allows Claude models to brute force breach 3 companies without authorization at some point during 141,000 evaluation runs.
To me, this is one of the clearest signs that data security is becoming more important than ever. AI models are getting incredibly capable, and that's exciting, but it also means the consequences of mistakes are growing. The smarter AI becomes, the more seriously we need to treat security, monitoring, and access control.