MAL-2026-782

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/ac-polyfills/MAL-2026-782.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-782
Published
2026-02-06T02:07:02Z
Modified
2026-09-21T05:30:06Z
Summary
Malicious code in ac-polyfills (npm)
Details

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

Source: amazon-inspector (98dfac851a08e8e8967e1386dadfd513226414b0ed65f6479a914479eb903878)

ac-polyfills@2.10.0 declares a preinstall lifecycle script in package.json (line 7-8) that runs wget to a hardcoded webhook.site collector URL (https://webhook.site/381d4406-8f87-4aab-961f-7a9496c21821/), sending the installer's username ($(whoami)), current working directory ($(pwd)), and hostname ($(hostname)) as query parameters. This fires automatically on npm install with no user interaction, exfiltrating installer identity and host information to a third-party webhook collector. The package name and shape are consistent with a dependency-confusion probe targeting an internal package name.

Source: ossf-package-analysis (c374cffaf0245c256691284c7b1c5dbeb5202f8d633efe3d23bc46c5c08806a9)

The OpenSSF Package Analysis project identified 'ac-polyfills' @ 2.10.0 (npm) as malicious.

It is considered malicious because:

  • The package executes one or more commands associated with malicious behavior.
Database specific 
{
    "malicious-packages-origins":  [
        {
            "import_time":  "2026-02-06T03:03:38.130497165Z",
            "modified_time":  "2026-02-06T02:07:02Z",
            "ranges":  [
                {
                    "events":  [
                        {
                            "introduced":  "0"
                        }
                    ],
                    "type":  "SEMVER"
                }
            ],
            "sha256":  "0a7d9d049932519bded5d12b8627523ef63dac69179b1ce873cf4cd8b7fe6849",
            "source":  "amazon-inspector"
        },
        {
            "id":  "RLMA-2026-01092",
            "import_time":  "2026-03-19T12:18:32.051171561Z",
            "modified_time":  "2026-03-18T12:37:36Z",
            "sha256":  "90cff5e7a441b510af31deb23e35a368e629b0b7bec79e1afa01d9fc37c935b7",
            "source":  "reversing-labs",
            "versions":  [
                "99.9.9"
            ]
        },
        {
            "id":  "IN-MAL-2026-020180",
            "import_time":  "2026-09-18T05:39:51.317096608Z",
            "modified_time":  "2026-09-18T05:25:24Z",
            "sha256":  "98dfac851a08e8e8967e1386dadfd513226414b0ed65f6479a914479eb903878",
            "source":  "amazon-inspector",
            "versions":  [
                "2.10.0"
            ]
        },
        {
            "import_time":  "2026-09-21T05:19:22.44602724Z",
            "modified_time":  "2026-09-17T23:15:53Z",
            "sha256":  "c374cffaf0245c256691284c7b1c5dbeb5202f8d633efe3d23bc46c5c08806a9",
            "source":  "ossf-package-analysis",
            "versions":  [
                "2.10.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / ac-polyfills

Package

Name
ac-polyfills
View open source insights on deps.dev
Purl
pkg:npm/ac-polyfills

Affected ranges

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

Affected versions

2.*
2.10.0
99.*
99.9.9

Database specific

cwes 
[
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files":  [
        {
            "path":  "package.json",
            "sha256":  "8c3dd253390bc47977519727afd6210fbebfb881f08387ec672899cfb33fa3c3",
            "tlsh":  "8a010234a330bb731ac256b204bd873fb531fba791156c0dafab221ad35ede200b9515"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "ac-polyfills-2.10.0.tgz",
            "hashes":  {
                "sha1":  "654356a88d7e44ae90799eee1025f3219831a98b",
                "sha512_sri":  "sha512-FTRwek4ZiQbzBe1kqZ0+rN3F4M/VCarYnS0NWA/IUaAfarVBDYOkJpF8erLXaFYIdaU0FYq0FQU9bzxaUuiQJw=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/ac-polyfills/MAL-2026-782.json"