MAL-2026-6544

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/chai-as-persisted/MAL-2026-6544.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-6544
Published
2026-06-27T02:32:25Z
Modified
2026-06-27T03:31:39.039006939Z
Summary
Malicious code in chai-as-persisted (npm)
Details

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

Source: amazon-inspector (5cf9c49450e0fa0d47be1b6ae27991f844868ff6c435d2082948b5feae862709)

The package's postinstall script (npm run smoke:pino) executes index.js, which spawns a detached node lib/initializeCaller.js child. That module hides the C2 URL in base64 strings stored under a fabricated local process.env object (keys DEV_API_KEY, DEV_SECRET_KEY, DEV_SECRET_VALUE) to defeat trivial string scanning. At install time it atob()-decodes the URL to https://www.ipregionchecker.org/api/ip-check-encrypted/3aeb34a37, POSTs to it via axios, and passes the response body to new Function.constructor('require', response), invoking it with require — executing attacker-controlled JavaScript with full Node module access on the installer's machine. The detached child.unref() keeps execution alive after npm install returns. The package name chai-as-persisted is a one-edit impersonation of the widely-used chai-as-promised; the shipped code is unrelated to chai (it pretends to be a pino-style logger middleware in index.js) and the package description/keywords (logger/stream/json) further misrepresent its purpose. This is a deliberate install-time RCE dropper distributed via a typosquat against chai-as-promised.

Database specific 
{
    "malicious-packages-origins": [
        {
            "versions": [
                "4.2.8"
            ],
            "source": "amazon-inspector",
            "modified_time": "2026-06-27T02:32:37Z",
            "sha256": "5cf9c49450e0fa0d47be1b6ae27991f844868ff6c435d2082948b5feae862709",
            "id": "IN-MAL-2026-007675",
            "ranges": [
                {
                    "type": "SEMVER",
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ]
                }
            ],
            "import_time": "2026-06-27T03:13:09.022299524Z"
        },
        {
            "versions": [
                "6.1.9"
            ],
            "ranges": [
                {
                    "type": "SEMVER",
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ]
                }
            ],
            "modified_time": "2026-06-27T02:32:25Z",
            "sha256": "611d869aaf9d1a8b945c83cc9982fd76cd49a26563d444af3cee98ccb5b6fbda",
            "id": "IN-MAL-2026-007674",
            "source": "amazon-inspector",
            "import_time": "2026-06-27T03:13:08.872578262Z"
        }
    ]
}
References
Credits

Affected packages

npm / chai-as-persisted

Package

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

Affected ranges

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

Affected versions

4.*
4.2.8
6.*
6.1.9

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 
{
    "package_integrity": [
        {
            "filename": "chai-as-persisted-4.2.8.tgz",
            "hashes": {
                "sha512_sri": "sha512-OF+BlgV0u9rUuZYMvemtJ0jtoutqeNa8QgGbcduKIJEtdzrvqyHPkXKiBLwOBjOV6NQZL/j/0XmtVd9hDuBy+Q==",
                "sha1": "f81cd3b1b4fa7eb57ab85af8d81f00ae94b10c89"
            }
        }
    ],
    "evidence_files": [
        {
            "path": "lib/initializeCaller.js",
            "tlsh": "4d119c4d71f82008042151e5b62f14126025e4673d8ad5e4bacc834b1fa667fbd53adf",
            "sha256": "76ca537732f161ae4d3a78b876390ddbab16e001c392a74009b31fb91ce4f89b"
        },
        {
            "path": "package.json",
            "tlsh": "d0019720debc4e2305ed25860c2a06037a615c175528fc2833e7922c0f9d5bb00ff22e",
            "sha256": "f061b9cb90a2c542ba90a73748290ff65dc070f811f75772bbfd0cc4453e0cbb"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/chai-as-persisted/MAL-2026-6544.json"