MAL-2026-6420 Malicious code in leo-cdk-lib (npm)

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.

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.