MAL-2026-5737

Import Source

https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/postcss-minify-selector-parser/MAL-2026-5737.json

JSON Data

https://api.osv.dev/v1/vulns/MAL-2026-5737

Aliases

GHSA-3m8w-m4vc-8f58

Published

2026-06-13T07:17:40Z

Modified

2026-06-24T02:16:23.073018332Z

Summary

Malicious code in postcss-minify-selector-parser (npm)

Details

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

Source: amazon-inspector (957f5cbb74f4dd4b4770e8c9cc1a8aac88a4450cb01dbc0fa5242c42e343f54c)

The package name impersonates the widely-used postcss-selector-parser library (which it also declares as a dependency and re-exports verbatim from src/selector-parser.js, providing cover for installers who mistype the real package). On top of that legitimate re-export, the package ships a sealed AES-GCM ciphertext as DEFAULTFINALENCODED_TEXT in src/config/defaults.js together with a hardcoded passphrase (default-dev-passphrase) and salt. src/pipeline/custom-codec-pipeline.js line 53 decrypts the blob and evaluates the cleartext via new Function("require", runnable)(require), handing the decrypted code full require capability on the installer's machine. This decode-and-eval path is reachable through the package's exported run / decodeAndRunPlain / runDefaultDecodedFunction API, through require('postcss-minify-selector-parser/cjs-runner'), and through the bundled runtime/lib.min.js and scripts/cjs-runner.js. The README documents none of this — it presents the package as a CSS selector parser. The combination of typosquat name, hidden encrypted payload, multi-layer custom codec pipeline (position-unit-codec + encode-decode-codec + AES-GCM) used solely to wrap that payload, and direct new Function(require) execution of the decrypted bytes is the canonical opaque-blob-eval supply-chain attack shape. Author field is empty, no repository URL is declared, license is generic ISC.

Source: ghsa-malware (34994969794d47c784e679fd2f442e839336789f6eacec233553ee18c462e024)

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": [
        {
            "source": "amazon-inspector",
            "sha256": "148543868c09650c18d4bb3014bbe60bad9b59e3a12d23ab16dddb3ebfa49fe1",
            "import_time": "2026-06-13T07:25:41.985638693Z",
            "modified_time": "2026-06-13T07:17:45Z",
            "id": "IN-MAL-2026-006349",
            "versions": [
                "1.0.15"
            ]
        },
        {
            "source": "amazon-inspector",
            "sha256": "1ba4406fdfc91cb0ec42b98b813ca5f6b859eae24f064be244293ae505c118a7",
            "import_time": "2026-06-13T07:25:41.709854891Z",
            "modified_time": "2026-06-13T07:17:44Z",
            "id": "IN-MAL-2026-006347",
            "versions": [
                "1.0.17"
            ]
        },
        {
            "versions": [
                "1.0.13"
            ],
            "sha256": "8a8af65bfa1b7dc7b28f718bff60b6fa76a786bbbbf92b570a1fc1ae0ecf1834",
            "import_time": "2026-06-13T07:25:41.460400188Z",
            "modified_time": "2026-06-13T07:17:42Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-006344"
        },
        {
            "modified_time": "2026-06-13T07:17:49Z",
            "sha256": "ca68c7aff52a1094d88d97893fbe50517c878a58043373be7b7cf70b3cdf4641",
            "versions": [
                "1.0.18"
            ],
            "import_time": "2026-06-13T07:25:42.63326585Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-006357"
        },
        {
            "source": "amazon-inspector",
            "sha256": "ec19903d44f3fd8e9ccddcf9477d64ea01b41a27d939a385454d66394d5e29a4",
            "import_time": "2026-06-13T07:25:42.177856798Z",
            "modified_time": "2026-06-13T07:17:46Z",
            "id": "IN-MAL-2026-006351",
            "versions": [
                "1.0.15"
            ]
        },
        {
            "source": "amazon-inspector",
            "sha256": "33c1cf9ccc165629c91ebab0a73464734b81a31ea6e845aa97740a2eb1554283",
            "import_time": "2026-06-13T07:25:41.593228529Z",
            "modified_time": "2026-06-13T07:17:43Z",
            "id": "IN-MAL-2026-006346",
            "versions": [
                "1.0.13"
            ]
        },
        {
            "import_time": "2026-06-13T07:25:42.096582455Z",
            "sha256": "5e05f8d236cfbc9ea0b7405a36cf28130f038c6a4af086f73883a25d68e7957d",
            "modified_time": "2026-06-13T07:17:46Z",
            "versions": [
                "1.0.14"
            ],
            "id": "IN-MAL-2026-006350",
            "source": "amazon-inspector"
        },
        {
            "versions": [
                "1.0.16"
            ],
            "sha256": "957f5cbb74f4dd4b4770e8c9cc1a8aac88a4450cb01dbc0fa5242c42e343f54c",
            "import_time": "2026-06-13T07:25:41.40143884Z",
            "modified_time": "2026-06-13T07:17:41Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-006343"
        },
        {
            "source": "amazon-inspector",
            "sha256": "d2d21adbc821f5e075a768a69ead3dd95330b0696159d2ac4d345806ad349d0d",
            "import_time": "2026-06-13T07:25:41.257004345Z",
            "modified_time": "2026-06-13T07:17:40Z",
            "id": "IN-MAL-2026-006341",
            "versions": [
                "2.0.1"
            ]
        },
        {
            "source": "amazon-inspector",
            "sha256": "f04cd7d7c790bb5aeae048484a106987c999cc74b9ff1ea369fa8177fc1e982e",
            "import_time": "2026-06-13T07:25:41.547191779Z",
            "modified_time": "2026-06-13T07:17:43Z",
            "id": "IN-MAL-2026-006345",
            "versions": [
                "1.0.16"
            ]
        },
        {
            "source": "amazon-inspector",
            "sha256": "f9aec6416f221aa55e21bbe373e6745933ad49efafa3565841b0bea17e3611e1",
            "import_time": "2026-06-13T07:25:41.345413317Z",
            "modified_time": "2026-06-13T07:17:41Z",
            "id": "IN-MAL-2026-006342",
            "versions": [
                "2.0.1"
            ]
        },
        {
            "import_time": "2026-06-13T07:25:42.413755812Z",
            "sha256": "51afcd0436194b387c2a4b619de4e504c65611ec3c20fb638042cd5af3811c26",
            "modified_time": "2026-06-13T07:17:48Z",
            "versions": [
                "1.0.11"
            ],
            "id": "IN-MAL-2026-006354",
            "source": "amazon-inspector"
        },
        {
            "source": "amazon-inspector",
            "sha256": "73e277b5c3910fc3758b78979f2a73284852d56f23e9ed59dac8a7d16dfffc0b",
            "import_time": "2026-06-13T07:25:42.23967175Z",
            "modified_time": "2026-06-13T07:17:46Z",
            "id": "IN-MAL-2026-006352",
            "versions": [
                "1.0.14"
            ]
        },
        {
            "id": "IN-MAL-2026-006358",
            "sha256": "8df97549294149dcf730bf7af26d825d7072f6fac463adaba700ec4da3c84730",
            "modified_time": "2026-06-13T07:17:52Z",
            "versions": [
                "1.0.12"
            ],
            "source": "amazon-inspector",
            "import_time": "2026-06-13T07:25:42.753854028Z"
        },
        {
            "import_time": "2026-06-13T07:25:42.349090024Z",
            "sha256": "93307191fd0206cb7dc1f18d1f7c1cc008f14cb6807784bf9ec6223097190eaf",
            "modified_time": "2026-06-13T07:17:47Z",
            "versions": [
                "1.0.11"
            ],
            "id": "IN-MAL-2026-006353",
            "source": "amazon-inspector"
        },
        {
            "modified_time": "2026-06-13T07:17:45Z",
            "sha256": "c6c670fb58865bb761a89229428b8568079889c02913d1619623619168e9e5e6",
            "versions": [
                "1.0.17"
            ],
            "import_time": "2026-06-13T07:25:41.859479966Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-006348"
        },
        {
            "import_time": "2026-06-13T07:25:42.563898834Z",
            "sha256": "f197723d2fd19b293e1dec876c169fc7dab6b2075dc936793452c9eace76de8a",
            "modified_time": "2026-06-13T07:17:49Z",
            "versions": [
                "1.0.18"
            ],
            "id": "IN-MAL-2026-006356",
            "source": "amazon-inspector"
        },
        {
            "source": "amazon-inspector",
            "sha256": "a6216015cbdb41be2fcb6e05cee8d9edb610c04b50cac6ca7577f14fb5e60be9",
            "import_time": "2026-06-13T07:25:42.486957071Z",
            "modified_time": "2026-06-13T07:17:48Z",
            "id": "IN-MAL-2026-006355",
            "versions": [
                "1.0.12"
            ]
        },
        {
            "modified_time": "2026-06-24T01:36:58Z",
            "sha256": "34994969794d47c784e679fd2f442e839336789f6eacec233553ee18c462e024",
            "import_time": "2026-06-24T01:59:16.917191055Z",
            "ranges": [
                {
                    "type": "SEMVER",
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ]
                }
            ],
            "source": "ghsa-malware",
            "id": "GHSA-3m8w-m4vc-8f58"
        }
    ]
}

References

Credits

- Amazon Inspector - FINDER
- - inspector-research@amazon.com

Affected packages

npm / postcss-minify-selector-parser

Package

Name: postcss-minify-selector-parser; View open source insights on deps.dev
Purl: pkg:npm/postcss-minify-selector-parser

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.0.11

1.0.12

1.0.13

1.0.14

1.0.15

1.0.16

1.0.17

1.0.18

2.*

2.0.1

Database specific

cwes

[
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    },
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    }
]

indicators

{
    "package_integrity": [
        {
            "filename": "postcss-minify-selector-parser-1.0.15.tgz",
            "hashes": {
                "sha1": "4e7eade3e30c0a65770c5a4eccd6313ee4b8a271",
                "sha512_sri": "sha512-zxCQf8/w+3FiA6WhdVWGajEZENyhEyzx3ppuHFPhX0xAtj0KfY9dGioYB667nGIjnOox2zQWToXFwVW5imoGjg=="
            }
        }
    ],
    "evidence_files": [
        {
            "tlsh": "367130c23cbf79c71d9bed64f0af0869186ca7113505f268aca953c80aeb275d123c8d",
            "sha256": "6a38f4170e8e82254423040d311c8164b3d928ebc00cd7a95a8f22bee75ce128",
            "path": "src/pipeline/custom-codec-pipeline.js"
        },
        {
            "tlsh": "7021f400de104d7335ca9d6e3c6a1446907a94870a84bc483b4587ac4f9d5bf51fb3ae",
            "sha256": "401217b0f03f7624b49dce3788bae66ffb7ff7de9cc6f8378742557a1f077740",
            "path": "package.json"
        },
        {
            "tlsh": "1f32cf7e7807033e81787bf1c8b46d266db22c3af06e3a154f7c40db6a46a07497256e",
            "sha256": "ef36cbe227547ce6b4153010cb9350e25a7c09fb3f0a385be77612fa06ba4b54",
            "path": "src/config/defaults.js"
        }
    ],
    "ips": [
        "104.16.5.34",
        "10.1.0.2"
    ]
}

source

"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/postcss-minify-selector-parser/MAL-2026-5737.json"