leo-confignpm
Malicious code in leo-config (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
The leo-config 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 containing GYP command-expansion syntax (<!(...)) at line 6 within the targets/sources fields. npm implicitly runs node-gyp rebuild whenever a binding.gyp is present — even without any 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. The package does not appear to ship genuine native source files matching a real native-addon build, so the binding.gyp's only practical purpose is to run the embedded shell command at install time. This is functionally identical to a malicious lifecycle hook and constitutes install-time arbitrary code execution on any machine that installs this package.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for leo-config (version 1.1.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging leo-config across your stack and pipelines.
If you installed it — respond
leo-config is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If leo-config was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks leo-config before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
- SafeDep · finder
Detect & block this
O3 blocks leo-config-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.