MAL-2026-13699

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/chai-as-bench/MAL-2026-13699.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13699
Published
2026-08-10T12:29:53Z
Modified
2026-08-10T13:05:03.204070187Z
Summary
Malicious code in chai-as-bench (npm)
Details

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

Source: amazon-inspector (487af469d8de2a3caa5e798df3a5d56e59b795c1ddc106abd1d38ed855b6fb17)

The package presents itself as a chai plugin (name resembles chai-as-promised, manifest description references chai assertions), but ships no chai-related functionality. index.js unconditionally loads lib/config.js on require(), and lib/config.js is a ~4 MB obfuscator.io payload with a 23,890-entry rotating string array, hex-obfuscated identifiers, and control-flow flattening. The remaining lib/ files (proto.js, multistream.js, transport.js) plus LICENSE are copied verbatim from the unrelated pino logger project as camouflage, and index.js itself only exports a no-op Express-style middleware ((_req,_res,next)=>next()). README contains placeholder yourusername GitHub URLs and generic author metadata (james@abscond.org). Heavy obfuscation of a multi-megabyte payload that runs on every require(), inside a package whose advertised purpose does not require any such code and whose surrounding files are stolen from an unrelated project, is the standard loader/stealer shape for an npm supply-chain plant targeting developers who mistype chai-as-promised.

Database specific 
{
    "malicious-packages-origins": [
        {
            "import_time": "2026-08-10T12:51:45.105379344Z",
            "id": "IN-MAL-2026-017267",
            "sha256": "487af469d8de2a3caa5e798df3a5d56e59b795c1ddc106abd1d38ed855b6fb17",
            "modified_time": "2026-08-10T12:29:53Z",
            "source": "amazon-inspector",
            "versions": [
                "7.0.3"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / chai-as-bench

Package

Name
chai-as-bench
View open source insights on deps.dev
Purl
pkg:npm/chai-as-bench

Affected ranges

Affected versions

7.*
7.0.3

Database specific

cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "lib/config.js",
            "tlsh": "d91685889245c523d2cc13a3be557aa9f13aa96584ccb607edf9bd6cb4bc807c0b5dd0",
            "sha256": "1176d4dea79d83166810bfe267ee4e31daa9c1b6d31c351c126bca6b1afb6a61"
        },
        {
            "path": "package.json",
            "tlsh": "91116660c8355da30add2590286a0626b2218e178e08bd1d33f3a01d6f9dd6f21bfe6d",
            "sha256": "700c69833e84260ec2ab5569d184a8a406f8629f2ce9b922b710ad732165a882"
        }
    ],
    "package_integrity": [
        {
            "filename": "chai-as-bench-7.0.3.tgz",
            "hashes": {
                "sha1": "3a838814e0860c40875174445dfd4022afb4ef83",
                "sha512_sri": "sha512-7oic+2UHOAchhGYsTLCeo7ID5P/ButB18qGin7D/u/7qgaQKEmOJMo7MH2lUWS78c3zn6TikL81FNTT8vOMfuw=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/chai-as-bench/MAL-2026-13699.json"