MAL-2026-5741

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/@achuthvp/postinstall-poc/MAL-2026-5741.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-5741
Published
2026-06-13T20:24:46Z
Modified
2026-06-13T20:46:41.519843531Z
Summary
Malicious code in @achuthvp/postinstall-poc (npm)
Details

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

Source: amazon-inspector (c3dc0d7b5fc216ae117dda9c492a6bbdff46e49ab53f069c2d525dab001bcdb9)

package.json declares scripts.postinstall = node postinstall.js. On every npm install, postinstall.js runs execSync('id') and POSTs a JSON body containing the id output, os.hostname(), platform, architecture, process.cwd(), and Node version to the hardcoded URL https://webhook.site/fceebb0d-9f11-4ac0-98db-6f6b3925f7d3 (postinstall.js line 14, exfil call constructed via https.request at line 21 with POST at line 24). The behavior is unconditional, undisclosed in the README (Does nothing much), and fires on a default install. Although the package self-describes as a POC, the install-time mechanism is identical to an active reconnaissance/exfiltration payload: any developer or CI machine installing this package leaks its identity (uid/gid/groups via id, hostname, cwd, platform) to an attacker-readable webhook bin.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-006379",
            "versions": [
                "1.0.2"
            ],
            "sha256": "8a5c98a52f068d49b6fbdf96d76a24df1f7807c41e53ab75d6270ca0ce64fb1a",
            "source": "amazon-inspector",
            "modified_time": "2026-06-13T20:24:47Z",
            "import_time": "2026-06-13T20:33:18.941844057Z"
        },
        {
            "id": "IN-MAL-2026-006381",
            "versions": [
                "1.0.3"
            ],
            "sha256": "91e690492c565ad314bb15d92061ec65f0f5a6622e3b20d9c4acf3170df13ac5",
            "source": "amazon-inspector",
            "modified_time": "2026-06-13T20:24:52Z",
            "import_time": "2026-06-13T20:33:18.994590214Z"
        },
        {
            "id": "IN-MAL-2026-006378",
            "import_time": "2026-06-13T20:33:18.916329426Z",
            "sha256": "972fb1c4637e2b6b3d0ed4a3d24b0f5a91fe190baf271328278eb756c9611e36",
            "source": "amazon-inspector",
            "modified_time": "2026-06-13T20:24:46Z",
            "versions": [
                "1.0.2"
            ]
        },
        {
            "id": "IN-MAL-2026-006380",
            "import_time": "2026-06-13T20:33:18.970252282Z",
            "sha256": "c3dc0d7b5fc216ae117dda9c492a6bbdff46e49ab53f069c2d525dab001bcdb9",
            "source": "amazon-inspector",
            "modified_time": "2026-06-13T20:24:52Z",
            "versions": [
                "1.0.3"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / @achuthvp/postinstall-poc

Package

Name
@achuthvp/postinstall-poc
View open source insights on deps.dev
Purl
pkg:npm/%40achuthvp%2Fpostinstall-poc

Affected ranges

Affected versions

1.*
1.0.2
1.0.3

Database specific

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"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/@achuthvp/postinstall-poc/MAL-2026-5741.json"
indicators 
{
    "evidence_files": [
        {
            "path": "postinstall.js",
            "sha256": "97ad818370207f92d58a2e9981e90fd5616b34c61cf5a2e09c4f78e187767fc5",
            "tlsh": "cb41674946f6a1741ab3bd9c936755066262c2173d04fcb8be4d0a601f4fa7c51f07ed"
        }
    ],
    "package_integrity": [
        {
            "filename": "postinstall-poc-1.0.2.tgz",
            "hashes": {
                "sha512_sri": "sha512-fTMzJ3V5X+66LuzDJyEOn1ryhrHusageUxt2Cemec7p6fP7cDU4jAEyTr6dK8xSPVZsGSBPSIL+J4a8BFDyb2A==",
                "sha1": "74c7ef7b1935a2f527bd7c97d666202c49088c7c"
            }
        }
    ],
    "ips": [
        "104.16.0.34",
        "10.1.0.2"
    ],
    "domains": [
        "webhook.site"
    ]
}