MAL-2026-13950

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/fmt-util-k7x2/MAL-2026-13950.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13950
Published
2026-08-13T17:20:45Z
Modified
2026-08-13T21:30:25.563190813Z
Summary
Malicious code in fmt-util-k7x2 (npm)
Details

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

Source: amazon-inspector (0e8613ffc5393a31685344c247925a5ef104f7daf3f0d2f45a51918adba7d344)

fmt-util-k7x2@1.0.1 advertises itself as a trivial string-formatting utility (index.js exports two-line pad/trim helpers), but its package.json declares a postinstall hook that runs setup.js on every npm install. setup.js probes a list of Twilio-internal hostnames (including code.hq.twilio.com, stage.twilio.com, twilio.jfrog.io, artifacts.twilio.com) and the AWS EC2 instance metadata endpoint at 169.254.169.254, then concatenates the per-target reachability results and sends them as a query string to a hardcoded external host at http://whstool.brkd.no/cb53e6db-e043-4383-89e9-853c9088ee5d?v=<results>. The per-install UUID callback identifies each victim uniquely, and the target set (internal corporate hostnames + cloud metadata service) matches the dependency-confusion reconnaissance pattern. The exfil destination is not owned by Twilio and is unrelated to the package's advertised purpose. The random-suffix name and mismatch between advertised functionality and postinstall behavior are consistent with a targeted dependency-confusion package aimed at Twilio build environments.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-017650",
            "import_time": "2026-08-13T17:24:45.966714677Z",
            "sha256": "0e8613ffc5393a31685344c247925a5ef104f7daf3f0d2f45a51918adba7d344",
            "versions": [
                "1.0.1"
            ],
            "source": "amazon-inspector",
            "modified_time": "2026-08-13T17:20:45Z"
        },
        {
            "id": "IN-MAL-2026-017703",
            "import_time": "2026-08-13T21:20:58.361715226Z",
            "sha256": "199c023d423783cbd5a697b3939d632b52e70029b86e59b63a69f4f298d39364",
            "modified_time": "2026-08-13T21:11:23Z",
            "source": "amazon-inspector",
            "versions": [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / fmt-util-k7x2

Package

Name
fmt-util-k7x2
View open source insights on deps.dev
Purl
pkg:npm/fmt-util-k7x2

Affected ranges

Affected versions

1.*
1.0.0
1.0.1

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"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "setup.js",
            "tlsh": "da11effb01f0a05d0fd4cf98f61ada5fa523e605e080ca54f1d516304dc717a9bb02d8",
            "sha256": "d543daee38bd6a69538e80f0cde5f4b4b81e2b2cd9ec84709b1b48be553efe3b"
        }
    ],
    "package_integrity": [
        {
            "filename": "fmt-util-k7x2-1.0.1.tgz",
            "hashes": {
                "sha512_sri": "sha512-9DTm4GsmZk2I4O+rTuZ2fZRd12CU0BgDyix1AJD3ol3+boJ5QUvGVAKtVP7P6K+0S6ggzkWqzSLXaZbpvvSfXQ==",
                "sha1": "604951d33fa14c01da8e1c8bb85dd2ff73e149ed"
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/fmt-util-k7x2/MAL-2026-13950.json"