MAL-2026-6420

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/leo-cdk-lib/MAL-2026-6420.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-6420
Published
2026-06-24T23:04:55Z
Modified
2026-06-25T08:01:28Z
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.

-= Per source details. Do not edit below this line.=-

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.

Database specific 
{
    "iocs":  {
        "urls":  [
            "https://safedep.io/miasma-worm-hits-leoplatform-20-npm-packages/"
        ]
    },
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-007468",
            "import_time":  "2026-06-25T07:47:50.61785631Z",
            "modified_time":  "2026-06-25T06:30:28Z",
            "sha256":  "0c00b5f0c306cb1af4497ed1726f1889b62a9b20d64de1dceb3181fbd7ca263b",
            "source":  "amazon-inspector",
            "versions":  [
                "0.0.2"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / leo-cdk-lib

Package

Name
leo-cdk-lib
View open source insights on deps.dev
Purl
pkg:npm/leo-cdk-lib

Affected ranges

Affected versions

0.*
0.0.2

Database specific

cwes 
[
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    },
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files":  [
        {
            "path":  "binding.gyp",
            "sha256":  "32d1bc728d8e504952083a6adc488c309a401c7df4dc8f47b382ce32e4aebe21",
            "tlsh":  "48c08c3ca9380d1029d958285168d402a4b142a3494e2a81fade60284fa840b2898bad"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "leo-cdk-lib-0.0.2.tgz",
            "hashes":  {
                "sha1":  "ef8bf6dd92cbc29ef8d23f3f0fa786ed20a856b1",
                "sha512_sri":  "sha512-/GYUgNuZuL7psrw6uPo6S9Af17dAqJGUECm37Eq//yi0w3uYCb55ciMrOD5dwTsq2kE8zlX7vJ9tF9qqfWGzyg=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/leo-cdk-lib/MAL-2026-6420.json"