MAL-2026-5844

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/numdifftools/MAL-2026-5844.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-5844
Aliases
  • GHSA-fv2r-6vq4-5x8r
Published
2026-06-15T23:39:12Z
Modified
2026-06-18T19:31:45.051685149Z
Summary
Malicious code in numdifftools (npm)
Details

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

Source: amazon-inspector (5c6d98d619244a4f34ba9c2ed85023e35f4064b0a45871edac806d1e8cdeff11)

The npm package numdifftools is an empty shell (zero-byte index.js) that exists solely to fire a preinstall lifecycle hook. The hook runs node -e to issue an HTTPS GET to https://webhook.site/cbfd239f-50d1-4bc6-9801-ba08ba9a2a4a/?host=numdiff-<hostname>, leaking the installer's os.hostname() to a third-party logging endpoint automatically on npm install before any code review opportunity. The package name reuses that of the well-known PyPI numerical-differentiation library numdifftools, capturing installs from developers who mistakenly run npm install numdifftools expecting the Python library's behavior. The package provides none of the advertised functionality — its only on-install effect is the host-identifier beacon.

Source: ghsa-malware (ecd4954558bd423a9adc4cee0b684f36395b22e0f539d7434f93d9297c5430aa)

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Database specific 
{
    "malicious-packages-origins": [
        {
            "ranges": [
                {
                    "type": "SEMVER",
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ]
                }
            ],
            "sha256": "ecd4954558bd423a9adc4cee0b684f36395b22e0f539d7434f93d9297c5430aa",
            "modified_time": "2026-06-15T23:39:14Z",
            "import_time": "2026-06-15T23:52:17.800130289Z",
            "source": "ghsa-malware",
            "id": "GHSA-fv2r-6vq4-5x8r"
        },
        {
            "sha256": "29da6a2a5913e2d3e9b92b1a5f7ba3b6e45b2afea2e911ebaeb123ebb776fd27",
            "import_time": "2026-06-18T19:20:03.166680171Z",
            "modified_time": "2026-06-18T19:10:23Z",
            "id": "IN-MAL-2026-007026",
            "versions": [
                "1.0.1"
            ],
            "source": "amazon-inspector"
        },
        {
            "sha256": "5c6d98d619244a4f34ba9c2ed85023e35f4064b0a45871edac806d1e8cdeff11",
            "import_time": "2026-06-18T19:20:03.280564224Z",
            "modified_time": "2026-06-18T19:10:24Z",
            "source": "amazon-inspector",
            "versions": [
                "1.0.0"
            ],
            "id": "IN-MAL-2026-007027"
        }
    ]
}
References
Credits

Affected packages

npm / numdifftools

Package

Name
numdifftools
View open source insights on deps.dev
Purl
pkg:npm/numdifftools

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.0
1.0.1

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "2c27d4b908add8b2069b10463530bf65d05de3e786c0f7bd776bfb76229df273",
            "path": "package.json",
            "tlsh": "25e0abf00d50f1333a8001a04997901af1e2dd09200859486fc3606941caa72a17a16c"
        }
    ]
}
cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    },
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    },
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/numdifftools/MAL-2026-5844.json"