MAL-2026-18249

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/noelc-css-blender/MAL-2026-18249.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-18249
Aliases
  • GHSA-cj2x-975v-jmwf
Published
2026-10-24T23:55:21Z
Modified
2026-10-26T06:45:16Z
Summary
Malicious code in noelc-css-blender (npm)
Details

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

Source: amazon-inspector (1af88de104874d73dc5e8853fec7d4ca8b0c2c1dfa26a3cff9e44fac7eb30ea6)

noelc-css-blender@2.1.11 declares itself as a 'tiny ESM utility for blending CSS custom-property token maps' with zero dependencies, but ships two heavily obfuscated single-line files totaling roughly 460 KB: index.mjs (~291 KB) and build-cache.mjs (~177 KB). Both consist of hex-named identifiers (_0x...) referencing large custom-encoded string arrays rather than readable code; the declared merge-two-token-maps functionality would require on the order of a dozen lines of plain JavaScript. The files carry fabricated 'auto-generated' header comments that misstate the package identity: index.mjs claims to be auto-generated by noelc-css-blender@2.2.1 (a different version than the actual 2.1.11 package), and build-cache.mjs claims to be auto-generated by tailwindcss-theme-kit@0.2.0, an unrelated package name. The headers additionally include 'restore from package-lock if corrupted' phrasing that functions as cover text discouraging inspection. package.json sets main: index.mjs, so any consumer that requires or imports noelc-css-blender executes the full obfuscated bundle at module load; there are no install lifecycle hooks, so the auto-executed surface is import-time rather than install-time. The string arrays use a custom (non-standard base64/XOR) encoding, so the specific sinks (network destinations, filesystem reads, child_process invocations) could not be extracted verbatim. The combination — massive obfuscated payload, trivial declared purpose, fabricated build-artifact header naming a different package, and import-time auto-execution via main — matches the carrier shape of credential-stealer / backdoor payloads rather than a legitimate CSS helper.

Source: ghsa-malware (dd5aa005958728cd9ab05682a4915f92e1c35734dde85dda3a6b747e02f7fe63)

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-cj2x-975v-jmwf",
            "import_time": "2026-10-25T01:00:16.33364337Z",
            "modified_time": "2026-10-24T23:55:21Z",
            "ranges": [
                {
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ],
                    "type": "SEMVER"
                }
            ],
            "sha256": "dd5aa005958728cd9ab05682a4915f92e1c35734dde85dda3a6b747e02f7fe63",
            "source": "ghsa-malware"
        },
        {
            "id": "IN-MAL-2026-021734",
            "import_time": "2026-10-26T06:39:38.815579787Z",
            "modified_time": "2026-10-26T05:48:19Z",
            "sha256": "05d7734bcef74c01baa8ac1bacadee6f35342aa98bdfd44f261b14de92f8e45a",
            "source": "amazon-inspector",
            "versions": [
                "2.2.0"
            ]
        },
        {
            "id": "IN-MAL-2026-021737",
            "import_time": "2026-10-26T06:39:39.123463815Z",
            "modified_time": "2026-10-26T05:48:49Z",
            "sha256": "1af88de104874d73dc5e8853fec7d4ca8b0c2c1dfa26a3cff9e44fac7eb30ea6",
            "source": "amazon-inspector",
            "versions": [
                "2.1.11"
            ]
        },
        {
            "id": "IN-MAL-2026-021735",
            "import_time": "2026-10-26T06:39:38.988141301Z",
            "modified_time": "2026-10-26T05:48:32Z",
            "sha256": "20e34a5a90c081279744326ebba1c8592911912e7951462c7ec0da338dbc00cd",
            "source": "amazon-inspector",
            "versions": [
                "2.1.9"
            ]
        },
        {
            "id": "IN-MAL-2026-021736",
            "import_time": "2026-10-26T06:39:39.058046947Z",
            "modified_time": "2026-10-26T05:48:40Z",
            "sha256": "376c97c3aa796232bb119520da720155254dcdec6966cf156e18bd8cd85500d6",
            "source": "amazon-inspector",
            "versions": [
                "2.2.1"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / noelc-css-blender

Package

Name
noelc-css-blender
View open source insights on deps.dev
Purl
pkg:npm/noelc-css-blender

Affected ranges

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

Affected versions

2.*
2.1.9
2.1.11
2.2.0
2.2.1

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"
    },
    {
        "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"
    },
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "index.mjs",
            "sha256": "62baab92771b1c4ad919ecac725164193892ea94519354fcc74556de0863a9fd",
            "tlsh": "2a54639163d92b61b5b97ed7a45f41e0cd30290cbd89f8c9f92c391c0a93512e6ceb72"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/noelc-css-blender/MAL-2026-18249.json"