AsyncAPI Malware Targets GitHub, Cloud, and AI API Credentials via Supply Chain Attack
A supply chain attack on the AsyncAPI npm project injected malware designed to steal a wide range of developer and cloud credentials, exploiting weak GitHub Actions workflows.
A sophisticated supply chain attack has compromised the AsyncAPI project on the npm registry, with attackers successfully republishing five package versions containing a hidden loader. This malware, identified by Microsoft, exploits vulnerabilities in GitHub Actions workflows and deploys a modular runtime named Miasma to pilfer credentials for critical services including GitHub, npm, cloud providers (AWS, Azure, GCP), and AI platforms like Anthropic and OpenAI.
The attack chain, which occurred on July 14, 2026, saw attackers republishing compromised versions within approximately ninety minutes. The malicious loader was designed to execute immediately upon the module's import, bypassing common security measures like the ignore-scripts setting that typically prevents execution of install scripts. This stealthy approach meant that even teams with robust security configurations could be vulnerable.
The Miasma runtime is a powerful framework capable of remote communication, maintaining persistence on compromised systems, and downloading additional modules. Its primary function in this attack is to harvest credentials. The malware specifically targets over one hundred environment variable names commonly used for storing secrets related to source control, package registries, cloud infrastructure, container platforms, secret managers, and AI services. This includes sensitive tokens like GITHUB_TOKEN, NPM_TOKEN, and various cloud provider API keys.
Beyond environment variables, Miasma also scans for credentials in common configuration files on disk, such as .npmrc, AWS credentials files, kubeconfig, SSH private keys, Vault tokens, and Docker configuration files. The presence of these harvesting modules, even if dormant in the initial sample, indicates a significant threat, as they could be activated remotely at a later stage.
The broad impact of this attack is amplified by the @asyncapi/specs package's integration into numerous other AsyncAPI tools. This means the compromise could have extended to developer laptops, CI/CD pipelines, containerized environments, and potentially production services. Any system that resolved the affected package versions during the brief exposure window was at risk.
Microsoft has urged affected organizations to immediately remove the compromised package versions, clear their npm and Yarn caches, and rotate all secrets that might have been exposed. Defenders are also advised to search for a file named sync.js in directories that mimic legitimate NodeJS support folders across Windows, macOS, and Linux systems.
The intrusion began with a malicious pull request against the asyncapi/generator repository, exploiting a misconfigured pull_request_target workflow that executed untrusted code and exposed a privileged bot token. This allowed attackers to push malicious commits, which were then released through the project's legitimate publishing path, lending an air of authenticity to the compromised packages.
This incident highlights the persistent threat of supply chain attacks within the software development ecosystem. The use of a modular runtime like Miasma, coupled with the exploitation of CI/CD pipelines and the targeting of a wide array of developer and cloud credentials, represents a significant escalation in the sophistication of these attacks. Organizations are reminded of the critical need for rigorous vetting of dependencies, secure CI/CD configurations, and comprehensive secret management practices.