Overview
- GitHub blocked and Microsoft temporarily removed about 70–73 repositories across Azure and related orgs after automated systems flagged malicious commits, with the rapid sweep occurring on June 5.
- Security firms say the commits planted configuration and payload code that triggers when developers open projects in AI coding tools such as Claude Code, Gemini CLI, Cursor, or VS Code and then harvests local and cloud credentials.
- Analysts trace the tooling to the Miasma family, a Mini Shai‑Hulud derivative linked to the threat actor TeamPCP, and report the payload can steal OIDC tokens used for build provenance and move laterally through cloud environments.
- The removals disrupted developer workflows by breaking GitHub Actions and CI pipelines, Microsoft has notified a small set of customers who may have pulled affected content, and investigators urge teams to assume compromise and rotate secrets.
- This incident follows a mid‑May compromise of Microsoft’s durabletask project and highlights broader 2026 trends of attackers targeting developer tooling, prompting calls for stricter extension controls, provenance checks, and locked dependency policies.