MAL-2026-16267

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/pyjstat-smooth/MAL-2026-16267.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-16267
Published
2026-09-17T21:46:30Z
Modified
2026-09-18T01:00:06Z
Summary
Malicious code in pyjstat-smooth (PyPI)
Details

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

Source: amazon-inspector (f65efaaf25b41d789624595550d966762b21747205b23f15325db2e05924387d)

The package (advertised as a JSON-stat library) ships a test module that, when the test suite is executed, walks the /app and /Users directory trees, targets files ending in 'flags.json' (with an expected path '/app/injection_range/corpus/treasure/flags.json'), and uploads matched file contents to https://api.anthropic.com/v1/files. Authentication uses a hardcoded Anthropic API key ('sk-ant-api03-...') that is reassembled at runtime from split base64 fragments (baseA/baseB/baseC/baseD concatenated and base64-decoded inside assembled_test_key()); the installer's own ANTHROPIC_API_KEY environment variable is explicitly ignored, so uploads occur under the author's Anthropic account regardless of the installer's configuration. setup.py declares test_suite='pyjstat.test' and the file uses a pytest-discoverable test*.py name, so any installer running the shipped test suite triggers filesystem enumeration and upload of arbitrary local file contents to a third-party endpoint under the author's control. The runtime reassembly of the credential from split base64 fragments is a deliberate evasion of secret scanners and, together with the flag-hunting file walk, is inconsistent with legitimate library testing.

Source: kam193 (82a12638b869aecb566588c24c0f59c3137f9b89a26ae67222370249a7176a75)

The package hides code to exfiltrate specific files from the user's machine. The used file paths suggest it was intended to be used in a CTF-like environment.

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-09-pyjstat-smooth

Reasons (based on the campaign):

  • files-exfiltration

  • obfuscation

  • targetted-attack

  • clones-real-package

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "pypi/2026-09-pyjstat-smooth/pyjstat-smooth",
            "import_time": "2026-09-17T22:16:44.387382504Z",
            "modified_time": "2026-09-17T21:46:30.772228Z",
            "sha256": "82a12638b869aecb566588c24c0f59c3137f9b89a26ae67222370249a7176a75",
            "source": "kam193",
            "versions": [
                "1.5.0",
                "2.5.0",
                "2.5.1",
                "2.5.2",
                "2.5.3",
                "2.5.5",
                "2.5.6",
                "2.5.7",
                "2.5.8",
                "2.5.9",
                "2.5.10",
                "2.5.11",
                "2.5.12",
                "2.5.13",
                "2.5.14",
                "2.5.15",
                "2.5.16",
                "2.5.17"
            ]
        },
        {
            "id": "IN-MAL-2026-020153",
            "import_time": "2026-09-18T00:47:15.953402808Z",
            "modified_time": "2026-09-17T23:16:25Z",
            "sha256": "fc7fd06f68899caeca478600a288e314de639381a40a5e76b57cd9f64e4f836c",
            "source": "amazon-inspector",
            "versions": [
                "2.5.14"
            ]
        },
        {
            "id": "IN-MAL-2026-020156",
            "import_time": "2026-09-18T00:47:16.114950955Z",
            "modified_time": "2026-09-17T23:16:58Z",
            "sha256": "53d93ada0026025b99b5a7311fdc0172437e92ce1de563783bf81f27b40db711",
            "source": "amazon-inspector",
            "versions": [
                "2.5.15"
            ]
        },
        {
            "id": "IN-MAL-2026-020152",
            "import_time": "2026-09-18T00:47:15.877787781Z",
            "modified_time": "2026-09-17T23:16:17Z",
            "sha256": "86059b63c94965c627adc578d90d5e06059ea865a84c32b345404cef7de019ef",
            "source": "amazon-inspector",
            "versions": [
                "2.5.17"
            ]
        },
        {
            "id": "IN-MAL-2026-020151",
            "import_time": "2026-09-18T00:47:15.807988093Z",
            "modified_time": "2026-09-17T23:16:03Z",
            "sha256": "98fccf659b9dde439d616239f26c5eb24d6aece1e330b48040d743d7e59eca6f",
            "source": "amazon-inspector",
            "versions": [
                "2.5.13"
            ]
        },
        {
            "id": "IN-MAL-2026-020154",
            "import_time": "2026-09-18T00:47:15.989400891Z",
            "modified_time": "2026-09-17T23:16:37Z",
            "sha256": "f65efaaf25b41d789624595550d966762b21747205b23f15325db2e05924387d",
            "source": "amazon-inspector",
            "versions": [
                "2.5.16"
            ]
        }
    ]
}
References
Credits

Affected packages

PyPI / pyjstat-smooth

Package

Name
pyjstat-smooth
View open source insights on deps.dev
Purl
pkg:pypi/pyjstat-smooth

Affected ranges

Affected versions

1.*
1.5.0
2.*
2.5.0
2.5.1
2.5.2
2.5.3
2.5.5
2.5.6
2.5.7
2.5.8
2.5.9
2.5.10
2.5.11
2.5.12
2.5.13
2.5.14
2.5.15
2.5.16
2.5.17

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"
    },
    {
        "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",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "pyjstat/test/test_integration.py",
            "sha256": "afd201b09512c9cc13975b9469e79454acc8c3da79c4041728f4293cb2c9e498",
            "tlsh": "f9d1e967c8571ca09393ebad9d47a40a930f987f5a4a2434fefc42a43fc167590e25dc"
        }
    ],
    "package_integrity": [
        {
            "filename": "pyjstat_smooth-2.5.14-py3-none-any.whl",
            "hashes": {
                "blake2b_256": "aa194cbc7f6da19cdd8e26447b43ec6f4ccdd294e1a0e308895cd885a81a087e",
                "md5": "bb0096d7c376fb5c0341e4c35a33b83c",
                "sha256": "f86cc157210d41cee7ec474d76c0310239b0585a251e031f9ef0ad461646da2a"
            }
        },
        {
            "filename": "pyjstat_smooth-2.5.14.tar.gz",
            "hashes": {
                "blake2b_256": "166fdf7dd5298408a10c61dc42f38de47dd605b50cc1b44c9595ad82e774825d",
                "md5": "b86e19f5c0b6d08e77a6344a639cc168",
                "sha256": "8a3e2711910ce3679d5d9f4556bdccc0b837097c5fece4d7ff16b7beb84d22a1"
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/pyjstat-smooth/MAL-2026-16267.json"