MAL-2026-14588

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/yaml-report-formatter/MAL-2026-14588.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-14588
Published
2026-08-28T09:14:39Z
Modified
2026-08-28T19:45:30.370941207Z
Summary
Malicious code in yaml-report-formatter (PyPI)
Details

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

Source: amazon-inspector (fd762621d7d279a25921e8f8c7d1a7e8040948bd3ac445ca9cabd8f200ce36f0)

Package presents itself as a YAML report formatter but its top-level src/yamlreportformatter/init.py starts a daemon thread on import that reads a token from /tmp/.sandbox_token, uses it with a router URL from an environment variable to fetch a private endpoint at /proxy/v2/me/threads, base64-encodes the response, splits it into 63-character DNS labels, and issues socket.getaddrinfo lookups against subdomains of dnshook.site to leak the data over a covert DNS side-channel. The exfiltration routine is hidden behind single-letter functions (_s, _r) and variables, wrapped in bare try/except that swallows all errors, and executed silently as a background thread. The advertised YAML-formatting purpose does not justify network activity of any kind, let alone chunked base64-in-DNS covert exfiltration to an attacker-controlled domain.

Source: kam193 (207190bd409999efcab9a56f8e536b6caf9c6a5ab92a134b77421f4bf1650f01)

During import, the package collects sensitive information and exfiltrates it using DNS queries.

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

Campaign: 2026-08-ekx-report-utils

Reasons (based on the campaign):

  • targetted-attack

  • exfiltration-generic

  • exfiltration-credentials

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "pypi/2026-08-ekx-report-utils/yaml-report-formatter",
            "modified_time": "2026-08-28T09:17:58.442936Z",
            "import_time": "2026-08-28T10:38:59.565654234Z",
            "source": "kam193",
            "sha256": "207190bd409999efcab9a56f8e536b6caf9c6a5ab92a134b77421f4bf1650f01",
            "versions": [
                "0.1.0",
                "0.2.0",
                "0.3.0"
            ]
        },
        {
            "id": "IN-MAL-2026-018807",
            "modified_time": "2026-08-28T16:45:43Z",
            "import_time": "2026-08-28T19:33:50.392419999Z",
            "source": "amazon-inspector",
            "sha256": "dbed337e7ec63c84550d86db8daabce978ddd5778e96986834d89255b92737bc",
            "versions": [
                "0.2.0"
            ]
        },
        {
            "id": "IN-MAL-2026-018810",
            "source": "amazon-inspector",
            "import_time": "2026-08-28T19:33:50.525627428Z",
            "modified_time": "2026-08-28T16:46:08Z",
            "sha256": "fd762621d7d279a25921e8f8c7d1a7e8040948bd3ac445ca9cabd8f200ce36f0",
            "versions": [
                "0.3.0"
            ]
        },
        {
            "id": "IN-MAL-2026-019044",
            "source": "amazon-inspector",
            "import_time": "2026-08-28T19:34:01.355773173Z",
            "modified_time": "2026-08-28T19:15:33Z",
            "sha256": "8777fcec55aeb9d6f53b2f8de77655dd38dbe74baec22df9e730c78b7168a7fa",
            "versions": [
                "0.1.0"
            ]
        }
    ]
}
References
Credits

Affected packages

PyPI / yaml-report-formatter

Package

Name
yaml-report-formatter
View open source insights on deps.dev
Purl
pkg:pypi/yaml-report-formatter

Affected ranges

Affected versions

0.*
0.1.0
0.2.0
0.3.0

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"
    },
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506"
    }
]
indicators 
{
    "package_integrity": [
        {
            "filename": "yaml_report_formatter-0.2.0-py3-none-any.whl",
            "hashes": {
                "md5": "603aca611b1c7e812721daaba17965b5",
                "blake2b_256": "11466e3a3524b9941bf9c68a5f118594dc6aeb05b7cd8d9becfca64db2efa084",
                "sha256": "4a6f8ff5ed8350913ebd49b59659c8f7da423b14596eab61903e2ad3e841d45a"
            }
        },
        {
            "filename": "yaml_report_formatter-0.2.0.tar.gz",
            "hashes": {
                "md5": "8bebeeb9f2678dbaa30aeda7b7c813ab",
                "blake2b_256": "2901eeccf15134f99b499ce988222fb1813ebca781e4f9eb8cfece1785fd8500",
                "sha256": "3f5e2a0d905cece5fdf97b2919c338f55c5ac67f764c79a09b0b6c75dfb2f342"
            }
        }
    ],
    "evidence_files": [
        {
            "path": "src/yaml_report_formatter/__init__.py",
            "tlsh": "3921230ae8290cb1c70349f4984986a577367a4b06019435bdfc7bd81f5dc751bb964c",
            "sha256": "ebe6d3931b83c07b7506b745f0c964738dc78c336f7d8266f51f891f202562b7"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/yaml-report-formatter/MAL-2026-14588.json"