registry / css-reading-display-polyfill / 1.0.0

css-reading-display-polyfill@1.0.0

Polyfill for CSS reading-flow property

AI Security Review

scanned 1d ago · by lpm-firewall-ai

The registry script executes system commands and transmits their output to a fixed webhook endpoint. Its behavior runs when the script is loaded.

Static reason

One or more suspicious static signals were detected.

Trigger

Loading thunderboltRegistry.js through a registry entry.

Impact

System and environment information is disclosed to an external endpoint.

Mechanism

The script invokes child_process commands to collect identity, environment, host, and network details, then sends encoded results through fetch and HTTPS requests.

Attack narrative

The package’s registry manifest points multiple registry entries to thunderboltRegistry.js. When loaded, that file runs system commands, collects host and environment information, and sends results to a fixed webhook endpoint.

AI rationale

The registry script contains active command execution and external transmission of collected system information, behavior unrelated to the stated CSS polyfill purpose. This is concrete malicious data exfiltration, so block publication.

Evidence

thunderboltRegistry.jsregistry-manifest.min.json

Network endpoints1

webhook.site/69bcd627-1871-4dda-b880-83b37ceac418

OSV advisory

OpenSSF/OSV

Advisory

css-reading-display-polyfill is described as a CSS polyfill but contains no polyfill code. When its thunderboltRegistry.js is loaded, it runs `id`, `whoami`, `uname -a`, `env`, `ifconfig` and `cat /etc/hosts` and sends the output with the hostname to a webhook.site collector. The file also exports stubs named after Wix Thunderbolt registry modules. The environment variables are sent as well, so tokens and API keys stored in them can be leaked. --- ## Source: amazon-inspector (a06a8966ab81cea21f3e94074bcdb0d72ea55a96be2d03989e12aa2f4d86ad66) thunderboltRegistry.js runs an IIFE at module load that invokes child_process.execSync to collect host identity (id, whoami, uname), the first 2000 bytes of the environment (env | head -100), network interfaces (ifconfig), and /etc/hosts, then transmits the results together with the hostname and Node version to a hardcoded webhook.site URL (https://webhook.site/69bcd627-1871-4dda-b880-83b37ceac418) via https.get and fetch. The package exports proxies for internal Wix thunderbolt registry names (thunderboltRegistry, siteAssetsRegistry, documentManagementRegistry, editorRegistry, corvidRegistry, dataBindingRegistry, and others) with a manifest pointing at static.parastorage.com/unpkg/, and the beacon is labelled beacon=rce-poc, consistent with a dependency-confusion probe against Wix build infrastructure. The exfiltrated environment typically contains CI secrets and cloud credentials, giving an installer-side credential-theft blast radius wherever the build pipeline resolves these internal names to this package.

css-reading-display-polyfill@1.0.0

AI Security Review

OSV advisory

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Source & flagged code