MAL-2026-13140

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/dolyame-ui-calendar/MAL-2026-13140.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13140
Published
2026-08-05T15:15:35Z
Modified
2026-08-05T15:52:42.384832606Z
Summary
Malicious code in dolyame-ui-calendar (npm)
Details

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

Source: amazon-inspector (1110e4e32da50573666c0e5f281db639994fad22ed178e2039b9689cc350c284)

The package advertises itself as a zero-dependency React calendar component library, but on require() of index.js it loads shim.js, which selects a platform-specific path, fetches an opaque binary from obfuscated Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev — hostnames assembled via array-join to evade string scanners), writes it to a hidden temp file, chmods 0755, and spawns it detached via /bin/sh -c on POSIX or cmd.exe /c start /b on Windows. A fallback path resolves DNS TXT records at c.<domain> and 0..N.<domain> under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru, concatenates the responses, base64-decodes them into an executable, and feeds the result into the same write/chmod/spawn sink — a covert channel that bypasses network egress controls blocking unknown HTTP hosts. Additional evasion appears in lib/telemetry.js, which uses require("child" + "process") and fs["chmod" + "Sync"] property-name concatenation and reimplements the same drop-and-exec primitives behind a Sentry-style analytics-SDK facade unreferenced from the entry point. Filenames and env-var opt-outs are named after telemetry/analytics to disguise the behavior. The fetched bytes are unpinned, unverified, and delivered from infrastructure unrelated to the advertised calendar-UI purpose.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "1110e4e32da50573666c0e5f281db639994fad22ed178e2039b9689cc350c284",
            "source": "amazon-inspector",
            "versions": [
                "35.1.8"
            ],
            "import_time": "2026-08-05T15:20:00.893345569Z",
            "modified_time": "2026-08-05T15:15:35Z",
            "id": "IN-MAL-2026-015628"
        }
    ]
}
References
Credits

Affected packages

npm / dolyame-ui-calendar

Package

Name
dolyame-ui-calendar
View open source insights on deps.dev
Purl
pkg:npm/dolyame-ui-calendar

Affected ranges

Affected versions

35.*
35.1.8

Database specific

indicators 
{
    "package_integrity": [
        {
            "hashes": {
                "sha1": "e726b5b53b1f2c4728b118bf017b392aed3c459f",
                "sha512_sri": "sha512-ycvButUfHzvSpqIELgw8FA5zH8NI1puRukExe64Do1x7+uNpTvDBZjnWQRjnRFWVXyvaY5JwnQiSMMnsfGfXQg=="
            },
            "filename": "dolyame-ui-calendar-35.1.8.tgz"
        }
    ],
    "evidence_files": [
        {
            "path": "_shim.js",
            "sha256": "c7236e3b1a45fb2668e4e3ae20a79d319a16b178b828e5a0729772e29e8fa7b6",
            "tlsh": "aba1865a16a630188bb0d7e4c71b5416f65bf66333808684fb9c69981fb316483b3efc"
        },
        {
            "path": "lib/telemetry.js",
            "sha256": "f2084dcb429c5dacbb79ff3cfe352339a9b44e6cb7e8b57391ccae9a27db982f",
            "tlsh": "8c835055566a242186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"
        }
    ]
}
cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/dolyame-ui-calendar/MAL-2026-13140.json"