OpenSSF/OSV advisory MAL-2026-6420 confirms this npm version as malicious. The `leo-cdk-lib` npm package was compromised as part of the Miasma worm campaign targeting the LeoPlatform npm ecosystem. On June 24, 2026, 20 LeoPlatform packages were published within a 3-second window by a threat actor who had taken over the npm account `czirker` belonging to the LeoPlatform organization.
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in leo-cdk-lib (npm)
Details
The `leo-cdk-lib` npm package was compromised as part of the Miasma worm campaign targeting the LeoPlatform npm ecosystem. On June 24, 2026, 20 LeoPlatform packages were published within a 3-second window by a threat actor who had taken over the npm account `czirker` belonging to the LeoPlatform organization.
The malicious payload is triggered automatically during `npm install` via a `binding.gyp` file using node-gyp command expansion (`<!(node index.js > /dev/null 2>&1 && echo stub.c)`), which bypasses lifecycle script scanners. The replaced `index.js` (~5.2 MB, obfuscated with ROT-N + AES-128-GCM encryption) deploys a multi-stage worm with the following capabilities:
- Credential theft: Targets npm, GitHub, PyPI, RubyGems, Kubernetes, HashiCorp Vault, AWS (IAM keys, Secrets Manager, IMDS), 1Password, JFrog Artifactory, and SSH keys. - AI tool targeting: Exfiltrates configuration files for Claude, Cursor, Gemini, and VS Code. - Worm propagation: Enumerates npm packages and auto-publishes version bumps to spread to other maintainers in the ecosystem. - GitHub persistence: Creates orphan `snapshot-<hex>` branches with fake "Dependabot Updates" workflows to maintain access after initial compromise.
Any system that installed this version should be considered fully compromised. Rotate all secrets immediately from a separate, clean machine. See the linked SafeDep report for full payload analysis, indicators of compromise, and remediation guidance.
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## Source: amazon-inspector (0c00b5f0c306cb1af4497ed1726f1889b62a9b20d64de1dceb3181fbd7ca263b) The package ships a binding.gyp at the root that contains GYP command-expansion syntax (<!(...)) inside the targets/sources fields. npm implicitly runs node-gyp rebuild whenever a binding.gyp is present, even without a declared install/postinstall script, and GYP evaluates <!(...) as a shell command during the configure step. This causes the embedded command to execute automatically on `npm install`, functionally equivalent to a lifecycle hook. The package does not ship corresponding native source files (.c/.cc/.cpp/.h) that would justify a real node-gyp build, indicating the binding.gyp's purpose is to run the embedded command rather than to build a native addon.