Open-source packages are now the primary attack surface used by threat actors. Rather than targeting enterprises directly, attackers are now compromising widely-used packages with a goal of reaching millions of CI/CD systems simultaneously through trusted releases.

Because these open-source packages form the backbone of modern enterprise workflows—including cloud pipelines, CI/CD systems, and developer tooling—attackers are increasingly targeting open-source organizations to poison these packages and publish them to trusted registries such as npm and the VS Code Marketplace, compromising hundreds of downstream organizations simultaneously through trusted releases installed by their developers.

Over the past year, AsyncAPI faced two supply chain attacks by TeamPCP and Miasma, compromising packages with up to 3.3+ million combined weekly downloads, such as:

• @asyncapi/specs (3.1M weekly)
• @asyncapi/generator (~129k weekly)
• Official VS Code extensions

This session presents the tactics, techniques, and procedures (TTPs) we saw used in both incidents, mapped directly to the MITRE ATT&CK framework. We will trace the end-to-end blast radius to illustrate how automated supply-chain compromises propagate into enterprise and public sector environments across Europe and Luxembourg.

Finally, attendees will gain actionable defense strategies and tools we have been using to tighten our security measures. We will showcase how we overhauled our release pipelines using:

• OIDC Trusted Publishing
• Automated CI/CD security scanning
• Hardened token isolation
• Least-privilege permission scopes on automation bots
• Continuous workflow auditing to catch anomalous triggers prior to artifact publication

Attendees will leave with practical checklists to audit their own GitHub Actions, build pipelines, and IDE extension supply chains against active threat groups.