MAL-2026-12599

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-types/MAL-2026-12599.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12599
Published
2026-08-05T14:07:55Z
Modified
2026-08-05T14:35:42.866816717Z
Summary
Malicious code in checkout-types (npm)
Details

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

Source: amazon-inspector (5d17ce247f3e7fa94b43e93af7597a9ae8a2a4008048a1ae8deb9352f45fc731)

On require of checkout-types, index.js loads vendor.js which runs setup() at top level. The code reconstructs C2 hostnames from split string arrays (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev) with a DNS TXT chunked-base64 fallback via sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. A platform-specific binary is downloaded, written to a temp path disguised as dotnetdiag<rand>.exe on Windows or.cache<rand> on Unix, chmod 0755, and spawned detached via cp.spawn("/bin/sh", ["-c", fp + " &"], {detached:true}) or cmd on Windows. Split-string obfuscation of destinations, DNS covert-channel fallback, cover-story file names, and detached spawn on module load result in arbitrary attacker-controlled code execution on the installer's host at require time.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "5d17ce247f3e7fa94b43e93af7597a9ae8a2a4008048a1ae8deb9352f45fc731",
            "id": "IN-MAL-2026-015177",
            "modified_time": "2026-08-05T14:07:55Z",
            "import_time": "2026-08-05T14:20:09.902403654Z",
            "source": "amazon-inspector",
            "versions": [
                "35.6.8"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / checkout-types

Package

Name
checkout-types
View open source insights on deps.dev
Purl
pkg:npm/checkout-types

Affected ranges

Affected versions

35.*
35.6.8

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "5e576c8a1a1cfc71afe9ad55ffafb039352454b43fe2b1a6388b603f3a8fa201",
            "path": "_vendor.js",
            "tlsh": "3ca1a75a16ab70184bb0a7f4c71b4416f657f5633380c284fb5c55985fb212483b2efc"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-0k/6HPW6XfilTs9YHcpSezZTIpWNpUSg7NohS/Io/B6UmV65Uy36NnaJp/+Zj+/URoJq0jJwm7aad4DBhExVZg==",
                "sha1": "17fa3b40ea49ee4b1762f83556fc1d14a7570329"
            },
            "filename": "checkout-types-35.6.8.tgz"
        }
    ]
}
cwes 
[
    {
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-types/MAL-2026-12599.json"