Cases › security breach › LR-2026-0584
Miasma worm compromises 73 Microsoft GitHub repositories via AI coding tools
Preliminary Why: 1 report: The Hacker News · subject to change · 1 independent report
Developing: a major or severe case captured in the last 72 hours. Later changes are logged on the corrections page.
Status: no action reported
No source states: loss or records, developer and model, agent tool, could do, deployer, industry.
The system was a set of developer repositories on GitHub, including Microsoft's Azure and Azure-Samples organisations, which developers open in AI coding tools. An attacker used previously compromised contributor credentials to push a malicious commit to the Azure/durabletask repository. The commit added configuration files that ran a credential-harvesting payload when a developer opened the repository in an AI coding tool. The payload harvested credentials and used them to propagate to further repositories. GitHub disabled the affected repositories in an automated sweep lasting 105 seconds. Microsoft said it had temporarily removed some repositories while it investigated. The malicious commit was reportedly backdated and used a skip-ci flag to avoid automated detection.
What happened
What was done
No source states an action or fix.
Risks
Primary24 incidents
Rising: 4 vs 0.2 a week
Read from the sources; not yet reviewed by a person.
Controls
Not yet read for controls. Controls that mitigate the primary risk:
Harness ApplicationSigned and verified components · Vetting of plug-ins, skills and dependencies · AI bill of materials · Vulnerability scanning of AI components · Model provenance checks · Least-privilege access for the agent
Infrastructure / targetSimilar incidents
Evidence
- What set it off exposed credentials
No source states: what the AI was doing, what it reached or did, when it was found, how many records were exposed, the direct loss, any court case, the cause, what was done.
Show the full account: 6 items from the primary sources
What happened, in order
- 2026-06-05T16:00:50Z GitHub disables 73 repositories in two automated waves over 105 seconds.
- 2026-05-16 Malicious payload core modules authored and C2 domain git-service[.]com registered.
- 2026-05-19 Initial compromise of the durabletask PyPI package; Microsoft confirmed and removed the packages.
- 2026-06-03 Second wave of Miasma-themed dead-drop repositories begins.
- 2026-06-05 Malicious commit pushed to Azure/durabletask using the same compromised contributor account.
- 2026-06-05/2026-06-06 Public disclosure and technical analysis by security researchers and news outlets.
Show every field, with its source and grade
What happened
Impact
LR-2026-0584 · version 1 · published 2026-11-01 after automatic checks; not yet checked field by field by a person · JSON