MAL-2026-17476

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-anchor-pos-fallback/MAL-2026-17476.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-17476
Published
2026-10-04T23:13:37Z
Modified
2026-10-04T23:30:06Z
Summary
Malicious code in css-anchor-pos-fallback (npm)
Details

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

Source: amazon-inspector (bd0a6c8e1448ffd9abb3732872ea3d49280a422d49524aaa57d0b89a73812f05)

The package advertises itself as a CSS anchor-position polyfill but on require executes an IIFE in thunderboltRegistry.js that runs id, whoami, uname -a, ifconfig/ip addr, and reads /etc/hosts, then POSTs the collected output along with hostname, platform, and Node version via fetch to the hardcoded external endpoint http://dxpoc.gt.tc/callback.php/. The module also exports keys named after Wix thunderbolt internal registries (thunderboltRegistry, siteAssetsRegistry, documentManagementRegistry, editorRegistry, corvidRegistry, etc.) with a bundled manifest referencing a parastorage.com unpkg URL, a shape consistent with dependency-confusion targeting of an internal Wix build pipeline. The advertised polyfill purpose is unrelated to shell execution, host reconnaissance, or outbound beaconing.

Database specific 
{
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-020882",
            "import_time":  "2026-10-04T23:16:30.194047624Z",
            "modified_time":  "2026-10-04T23:13:37Z",
            "sha256":  "bd0a6c8e1448ffd9abb3732872ea3d49280a422d49524aaa57d0b89a73812f05",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / css-anchor-pos-fallback

Package

Name
css-anchor-pos-fallback
View open source insights on deps.dev
Purl
pkg:npm/css-anchor-pos-fallback

Affected ranges

Affected versions

1.*
1.0.0

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":  "thunderboltRegistry.js",
            "sha256":  "b5389ce14f205c3930883356fdb46e32a129e17e008c100eae468409b3afaa4e",
            "tlsh":  "697144a5b99df02165c33438cb7f4049b4bbc6672d6caee0744999b01f7985c01be6f4"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "css-anchor-pos-fallback-1.0.0.tgz",
            "hashes":  {
                "sha1":  "36551a24f198a0d6b93ed4fde353c98f43ffa06e",
                "sha512_sri":  "sha512-So/Lb4vSsrichmCat3kQSUgOXWLxqNzxC8BGSXIrLBGjzmuFNfyNyUtha/KAXVO9CPabz5egcGQT/7iSzjHLYQ=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-anchor-pos-fallback/MAL-2026-17476.json"