MAL-2026-17239

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/test-agency-assignment/MAL-2026-17239.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-17239
Published
2026-09-28T22:03:04Z
Modified
2026-09-28T22:30:06Z
Summary
Malicious code in test-agency-assignment (npm)
Details

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

Source: amazon-inspector (dcdf62e1c1eb44ca7a29ed37c12bdb71883025a46c5066e58c9228f0dfe782c2)

package.json declares a postinstall lifecycle script wscript.exe 4444.vbs, causing the VBS file shipped in the tarball to run automatically on npm install on Windows hosts. 4444.vbs contains a hand-rolled multi-layer decoder (Base64, an XOR-masked AES S-box, ChaCha20-IETF, additional XOR) that concatenates hundreds of embedded ~2KiB Base64 chunks stored in ArtifactBundleHX(...), decrypts them, writes the resulting PowerShell loader to a randomly named file under %TEMP% (pf<rand>.dat), and invokes powershell.exe against it. In-file comments describe the handoff to PowerShell as being for process hollowing. The file header presents a benign 'Device Telemetry Aggregator' cover story that does not match the shipped behavior. The package's only functional content is this dropper; installing the package on Windows results in arbitrary attacker-controlled code execution on the installer's host.

Database specific 
{
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-020611",
            "import_time":  "2026-09-28T22:18:22.479197758Z",
            "modified_time":  "2026-09-28T22:03:04Z",
            "sha256":  "dcdf62e1c1eb44ca7a29ed37c12bdb71883025a46c5066e58c9228f0dfe782c2",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.2"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / test-agency-assignment

Package

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

Affected ranges

Affected versions

1.*
1.0.2

Database specific

cwes 
[
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files":  [
        {
            "path":  "package.json",
            "sha256":  "60b89a83cb5dfa6b32a01f4332fed1392196cc0d4b668322e8badcd2142d36e6",
            "tlsh":  "90d0a7274945963329f4475409718416b5128f1f10314c0bb2f3651890e36b24889b06"
        },
        {
            "path":  "4444.vbs",
            "sha256":  "89a31ec0719b2137938c892385823ffb993d2d903e1fdfe17b246ba88531609a",
            "tlsh":  "daf4f034658a68abb63bcafeace6c72935147c053040606c35deb6581bfdcd15bda0f8"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "test-agency-assignment-1.0.2.tgz",
            "hashes":  {
                "sha1":  "75c09d06aa8e36ddb9c4fa79ae9359625bf338b9",
                "sha512_sri":  "sha512-QFNwa4A6D07b6XzW/pZORsllAx2DWxB0CtbT8z32V/4gghmBVQQaWJ8Ik92AUwhsI+3JLYYI3R2+9Ava6LSRxA=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/test-agency-assignment/MAL-2026-17239.json"