MAL-2026-5436

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-signer/MAL-2026-5436.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-5436
Published
2026-06-09T17:44:33Z
Modified
2026-06-09T18:01:33Z
Summary
Malicious code in checkout-signer (npm)
Details

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

Source: amazon-inspector (f6add4dfcaaf79ce107ac8026032b47540def183a121be2266891644c90f10c8)

Package replicates the API surface of an internal Exodus package (generateMnemonicSigningKeys, signDirectPaymentMultiChain, signCapture, signRefund, signCharge, signCancelSubscription exported from src/index.js), where each export throws an error rather than implementing the real signing logic. On npm install, src/canary.js (line 6) performs a DNS lookup and HTTPS GET to a hardcoded serveo.net tunnel host (https://96e03fa6c292469a-172-245-86-254.serveousercontent.com/canary-install), sending the package name and version. Any organization that pulls this from the public registry believing it to be the internal Exodus dependency reveals their install (org / CI host identification via DNS + HTTPS source) to the operator of the tunnel. README claims the package performs only a DNS lookup with no data transmission, contradicting the actual HTTPS GET with query parameters. The beacon destination is a mutable serveo tunnel pointing at a residential-style IP (172.245.86.254), which is operator-controllable infrastructure rather than a stable vendor endpoint. Regardless of any stated 'authorized research' framing, the structure — divergent-API namespace-abuse shape plus an unconsented install-time beacon to a tunneling host — is the live dependency-confusion attack pattern.

Database specific 
{
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-005116",
            "import_time":  "2026-06-09T17:45:55.358577556Z",
            "modified_time":  "2026-06-09T17:44:33Z",
            "sha256":  "b1f3068ce30a667baae76fe67d718a1586a173eeddad17eef2347aca53bb505b",
            "source":  "amazon-inspector",
            "versions":  [
                "99.0.0-canary.1"
            ]
        },
        {
            "id":  "IN-MAL-2026-005115",
            "import_time":  "2026-06-09T17:45:55.314724481Z",
            "modified_time":  "2026-06-09T17:44:33Z",
            "sha256":  "f6add4dfcaaf79ce107ac8026032b47540def183a121be2266891644c90f10c8",
            "source":  "amazon-inspector",
            "versions":  [
                "99.0.0-canary.1"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / checkout-signer

Package

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

Affected ranges

Affected versions

99.*
99.0.0-canary.1

Database specific

cwes 
[
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    }
]
indicators 
{
    "domains":  [
        "96e03fa6c292469a-172-245-86-254.serveousercontent.com"
    ],
    "evidence_files":  [
        {
            "path":  "src/index.js",
            "sha256":  "8df05b04ab1173592b08d71dea34f5998519f445526493f61ab3dd9dc0145a5a",
            "tlsh":  "63e07d5f0961337a1d8bd441d49794213fa2560ad0fd89a60c8d521f75035348eff0c5"
        },
        {
            "path":  "src/canary.js",
            "sha256":  "16502b9065d4976ebb34fd49d0fb75f3cd0e64cf8d35872b419a6b6752485d51",
            "tlsh":  "37e06ffe4fd0a33a56701bc9f080a54fe707e3283085a2c1d69822a249c28f0ae218f0"
        },
        {
            "path":  "README.md",
            "sha256":  "69d46c690982f0b1ac2e681bfef34ec6233feaadc305a67a90c1e58f57ab4262",
            "tlsh":  "48e0c05491f2463216f568f5a0d205906b3cf07066174ca9bbca560f6308aabc30768e"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "checkout-signer-99.0.0-canary.1.tgz",
            "hashes":  {
                "sha1":  "d59c5a580d513763f2d9929be6c8c50893a6ab4e",
                "sha512_sri":  "sha512-E9j2LlYeYsAYYTQ0mgAKR4YMLTyMj2vx2mwWxsPrhhOow3+46mmiyZRh7RcxqW2l+0Pa0AdXr6yr+FE78E1qkA=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-signer/MAL-2026-5436.json"