MAL-2026-12433

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/saas-f-lego-landings/MAL-2026-12433.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12433
Published
2026-08-05T12:35:49Z
Modified
2026-08-05T13:35:53.923232902Z
Summary
Malicious code in saas-f-lego-landings (npm)
Details

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

Source: amazon-inspector (0c96f58511420dcd956adbe21ee52dd1acae9956f5b562887a5c6659679fb52d)

saas-f-lego-landings@20.7.5 executes a native binary dropper as a side effect of loading the package. index.js unconditionally requires./support.js, which on load selects a platform-specific endpoint, fetches an executable over HTTPS from obfuscated Cloudflare Workers hosts (oob-worker.cf10{0,1,2}-*.workers.dev) with a DNS TXT-record fallback to *.dl.well1.site, writes it to /tmp/.cache* on Unix or %TEMP%/dotnetdiag.exe on Windows, chmods 0755, and spawns it detached via /bin/sh -c or cmd /c start. Destination hostnames are reconstructed at runtime via string-split.join() (e.g. ["oob","-worker.cf102-baf.workers.dev"].join("")), childprocess is required from inside a nested function, and os accessors are indexed via osm — all evasion patterns rather than legitimate configuration. The tarball also ships lib/telemetry.js, an ~80KB module styled as a Sentry-like analytics SDK that contains the same base64→write→chmod 755→spawn /bin/sh -c dropper primitives (WorkerHost/ServiceDiscovery/HttpTransport, Buffer.from(chunks,"base64"), fs"chmod"+"Sync"); it is not referenced by index.js but corroborates the observability-SDK cover story. Deceptive filenames (dotnetdiag_.exe,.cache_*), multi-mirror C2, DNS-TXT covert-channel fallback, and an env-var opt-out cover-story are consistent with an intentional stage-2 loader.

Database specific 
{
    "malicious-packages-origins": [
        {
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-014721",
            "import_time": "2026-08-05T13:08:40.748956807Z",
            "versions": [
                "20.7.5"
            ],
            "modified_time": "2026-08-05T12:35:49Z",
            "sha256": "0c96f58511420dcd956adbe21ee52dd1acae9956f5b562887a5c6659679fb52d"
        }
    ]
}
References
Credits

Affected packages

npm / saas-f-lego-landings

Package

Name
saas-f-lego-landings
View open source insights on deps.dev
Purl
pkg:npm/saas-f-lego-landings

Affected ranges

Affected versions

20.*
20.7.5

Database specific

cwes 
[
    {
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature."
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/saas-f-lego-landings/MAL-2026-12433.json"
indicators 
{
    "evidence_files": [
        {
            "tlsh": "24a1869616aa301c4bb0abf4c6174419f65bf26333808294f75c69945fb312483b2ffc",
            "sha256": "ce656641c749100b2d8a0f75cd36eded23214e6e98e5db13eb8555e9b04b3820",
            "path": "_support.js"
        },
        {
            "tlsh": "81835056566a142186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc",
            "sha256": "135f1960df9fd80bf30b6e19922199a10133190fe2c432510a0abdc61c6f52b9",
            "path": "lib/telemetry.js"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha1": "d65ca7be13672f856a5c6f69867bc83b2ddfe49a",
                "sha512_sri": "sha512-PHekJaeDrKuplcR6/mPi5NeZmuS35Iuit2WAKA6rQc1PLK7v7rulsaywdBO58FwB+6/A0TbPGJb8Ci2EFCONYA=="
            },
            "filename": "saas-f-lego-landings-20.7.5.tgz"
        }
    ]
}