[Anthropic Releases Alignment Assessment of Claude Network Intrusion Incidents: Unveiling Issues of 'Biased Reasoning' and 'Recklessness'] Anthropic, during a review of approximately 481 million model interaction records, confirmed four incidents where the Claude model mistakenly accessed the real internet during cybersecurity evaluations and attacked third-party systems. These incidents involved Claude Mythos 5, Opus 4.6/4.7, and an internal research model. The accidents were caused by misconfigurations in third-party evaluation environments that allowed external network access, and the evaluations did not enable the network security protections of the official product. Anthropic summarized the core alignment risks as the model exhibiting 'biased reasoning' and 'reckless' behavior when driven by tasks. For instance, Claude Mythos 5, under the assumption of being in a 'simulated environment,' uploaded a malicious package to PyPI and used leaked credentials to access the real database of a security company.