MAL-2026-6718

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/test-pkg-yarn/MAL-2026-6718.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-6718
Published
2026-07-01T20:47:51Z
Modified
2026-07-01T21:16:41.838910467Z
Summary
Malicious code in test-pkg-yarn (npm)
Details

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

Source: amazon-inspector (40b74339843ee482f3f135dd43e855f1f30758e20857333e0e6153748888769a)

package.json declares bin: { "node": "./shim.js" }, causing npm/yarn to symlink node in node_modules/.bin (and in a system bin dir on global install) to a package-controlled script. Subsequent invocations of node resolved through that PATH entry execute shim.js instead of the real Node.js runtime, redirecting any tooling that expects node to attacker-controlled code. In addition, scripts.postinstall runs bun shim.js || node shim.js, and shim.js unconditionally invokes OS commands at install time via child_process.execSync — spawning a GUI calculator (calc on Windows, gnome-calculator on Linux, open -a Calculator on macOS), opening a URL in the user's browser, and writing a marker file to /tmp/.bun-npm-pwned. The package self-identifies as 'BunnyHijack PoC - yarn variant' with the console message '[!] PATH POISONED - test-pkg-yarn just hijacked your node command.' Although framed as a proof-of-concept and not currently exfiltrating data, the behavior is real install-time code execution against any developer who installs the package and a persistent hijack of the node command in PATH.

Database specific 
{
    "malicious-packages-origins": [
        {
            "versions": [
                "1.0.2"
            ],
            "sha256": "11e7c03fcf57c76835129d9a0c35cc8b0ad262e164929fed2b0452f2d83eb44f",
            "modified_time": "2026-07-01T20:47:51Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-007897",
            "import_time": "2026-07-01T21:04:20.755909312Z"
        },
        {
            "versions": [
                "1.0.1"
            ],
            "sha256": "40b74339843ee482f3f135dd43e855f1f30758e20857333e0e6153748888769a",
            "modified_time": "2026-07-01T20:48:08Z",
            "source": "amazon-inspector",
            "import_time": "2026-07-01T21:04:20.868827675Z",
            "id": "IN-MAL-2026-007899"
        },
        {
            "versions": [
                "1.0.0"
            ],
            "sha256": "c94364f82778798bd6d381c0359adb0f0eb92676036c117640d0370810b7ab2e",
            "modified_time": "2026-07-01T20:47:57Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-007898",
            "import_time": "2026-07-01T21:04:20.787779869Z"
        }
    ]
}
References
Credits

Affected packages

npm / test-pkg-yarn

Package

Name
test-pkg-yarn
View open source insights on deps.dev
Purl
pkg:npm/test-pkg-yarn

Affected ranges

Affected versions

1.*
1.0.0
1.0.1
1.0.2

Database specific

indicators 
{
    "package_integrity": [
        {
            "filename": "test-pkg-yarn-1.0.2.tgz",
            "hashes": {
                "sha512_sri": "sha512-ZsZYjMO1aXwPqfM07+ryLjfRDcXPnQ/ZvvfsZrSpGi4Kixj+NU6EfcJfwRhtJUK0wdmmiIdHUoPx26tMDvYMCg==",
                "sha1": "932e1e7951721bf60858bb5db11e58073c676b1e"
            }
        }
    ],
    "evidence_files": [
        {
            "sha256": "0a5b47939c9280af09b961619c386fea57ca3b197dd5003b41ceca244e89bbc7",
            "path": "package.json",
            "tlsh": "dbd02b1088b1577325cd38905d6da403673c4b4780043c2c53d7119cab4a7bb08b9255"
        },
        {
            "sha256": "3a0197615cc4fd1bbea22a9355a5d69fdbfe7a23f2a21c5a5afc17b4e6b5f6fa",
            "path": "shim.js",
            "tlsh": "3f316062c2e193b16ef619c2568b443175abdaa37240ffa4f29ec2225f4901203f74b8"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/test-pkg-yarn/MAL-2026-6718.json"
cwes 
[
    {
        "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",
        "cweId": "CWE-506"
    },
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506"
    }
]