MAL-2026-6200

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/assert-kit/MAL-2026-6200.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-6200
Aliases
  • GHSA-748x-3gxw-v7xv
Published
2026-06-19T08:08:40Z
Modified
2026-06-23T22:46:24Z
Summary
Malicious code in assert-kit (npm)
Details

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

Source: amazon-inspector (6e21fa9c37e9944a00f7e85c7476f8fd4dc6bcd1f8fcd064a90488ef93d5bd12)

assert-kit@4.3.2 impersonates the chai assertion library (bundles chai's source, contributors, and API surface under a different author and homepage assertkit.com) and adds a remote-code execution backdoor. On require('assert-kit'), index.js calls validate_assert() at module top level, which spawns a detached node subprocess running lib/chai/utils/addAssertion.js with stdio:'ignore' and unref() so the child survives the consumer process. lib/chai/utils/addAssertion.js is heavily obfuscator.io-obfuscated; after string-array decoding it requires 'https', performs an https.get to a URL assembled from decoded strings, and passes the response body to new Function('require', body)(require) — running attacker-controlled JavaScript with full Node capabilities (filesystem, network, child_process, environment). Any project that installs and require()s this package executes whatever code the operator currently serves from the hardcoded endpoint, in a backgrounded process the user cannot easily see or terminate.

Source: ghsa-malware (a42618d9b7dbd1c89448d216bbe53a557d2a1e95064936fcafe9ffece01c61a9)

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "GHSA-748x-3gxw-v7xv",
            "import_time": "2026-06-19T08:13:49.238584093Z",
            "modified_time": "2026-06-19T08:08:40Z",
            "ranges": [
                {
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ],
                    "type": "SEMVER"
                }
            ],
            "sha256": "a42618d9b7dbd1c89448d216bbe53a557d2a1e95064936fcafe9ffece01c61a9",
            "source": "ghsa-malware"
        },
        {
            "id": "IN-MAL-2026-007375",
            "import_time": "2026-06-23T22:31:27.402564394Z",
            "modified_time": "2026-06-23T21:43:31Z",
            "sha256": "6e21fa9c37e9944a00f7e85c7476f8fd4dc6bcd1f8fcd064a90488ef93d5bd12",
            "source": "amazon-inspector",
            "versions": [
                "4.3.2"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / assert-kit

Package

Name
assert-kit
View open source insights on deps.dev
Purl
pkg:npm/assert-kit

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

4.*
4.3.2

Database specific

cwes 
[
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    },
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "lib/chai/utils/addAssertion.js",
            "sha256": "3b357f9fe65878e583defafa3797dd69bc859c744705bc303c91c1c2e39d1033",
            "tlsh": "2791fe8626c1798172479faf3a3a54d5d8598e82ffc404a3f61ab898fce4624d4c1bb4"
        },
        {
            "path": "index.js",
            "sha256": "e045f0b4ff409bcc00b1c2e74f687501740197295b26b41587f94c7d2f39c3d3",
            "tlsh": "19f0dcfa02c1aa286d31bbf18007442623e3c172f24040a8fafd90d26657b835233cbd"
        },
        {
            "path": "package.json",
            "sha256": "6d6812ec5c82c2228c6df03fc47bdfacfcd02195a79352cb2363ff803df275cd",
            "tlsh": "0b214460cda89ea31ad622a8243e0013b1318e438d54fc1d37aa275d0f8e06f757daad"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/assert-kit/MAL-2026-6200.json"