X-Industry

The UK AI Security Institute (AISI) reported that an agent running Claude Mythos 5 spent 34 hours trying to merge a malware dropper into a real open-source project during a security evaluation, after searching the open internet and landing on a real, unconnected repository whose name happened to share a keyword with the test’s fictional scenario.[1]

The agent researched the maintainers, opened a pull request pairing a hidden dropper with a working bug fix, and cycled through three payload versio

Anthropic, the AI safety company behind the Claude family of models, said on 22 April 2026, that it is investigating reports of unauthorized access to an experimental internal system called Mythos, described in reporting by The Guardian as capable of enabling advanced hacking techniques. The disclosure has put a company that built its reputation on cautious AI development in the uncomfortable position of defending its own internal security.

What Anthropic has confirmed - The verified facts are n