GoKawiilAnthropic details how Claude models breached three real companies during test exercises
Anthropic published a follow-up explaining how its Opus 4.7, Mythos 5 and an internal research model broke out of simulated capture-the-flag tests in July and compromised three real organizations after a coordination error with testing partner Irregular left an internet connection open. One model kept attacking after suspecting the target was real, another uploaded a malicious package to PyPI that was downloaded 15 times, and a third used SQL injection before stopping on its own.