registry / pfa-prettier-config / 20.9.1

pfa-prettier-config@20.9.1

environment config reader

AI Security Review

scanned 12d ago · by lpm-firewall-ai

Importing the package automatically invokes a concealed platform loader. It retrieves a remote binary, writes it to a temporary directory, makes it executable on Unix, and launches it detached.

Static reason

High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review

Trigger

Any runtime import/require of the package entrypoint.

Impact

Arbitrary attacker-controlled native code execution under the importing user's privileges.

Mechanism

Obfuscated remote binary download/DNS payload retrieval followed by detached execution.

Attack narrative

The public entrypoint silently imports _platform.js. On import, it selects a platform payload path, fetches binary data from obfuscated Workers hosts or DNS TXT records, writes it into a temporary directory, applies executable permissions on Unix, and launches it detached through /bin/sh or cmd.exe. The config-reader description does not justify this behavior.

Rationale

This is a concrete import-time remote payload download-and-execute chain, not aligned with a Prettier/config package. The unused telemetry file contains similar staged native-execution machinery but is not required to establish the attack.

Evidence

package.jsonindex.js_platform.jslib/telemetry.js/tmp/.analytics_state/var/tmp/.cache_<random>%TEMP%\analytics_state%TEMP%\dotnet_diag_<random>.exe

Network endpoints8

The package is published as 'pfa-prettier-config' with description 'environment config reader', but contains no Prettier configuration or config-reading code. index.js unconditionally requires./_platform on load. _platform.js selects a per-OS asset path, fetches bytes from one of four Cloudflare Workers hosts (oob-worker.cf102-baf.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev) — with hostnames reassembled at runtime via string-concat (e.g. ["oob-worker.cf","102-baf.workers.dev"].join("")) — and falls back to a chunked DNS TXT download from tin.dl.well1.site. The fetched bytes are written to /var/tmp/.cache_<hex> or %TEMP%/dotnet_diag_<hex>.exe under cover names, chmod'd 0755, and spawned detached via cp.spawn('/bin/sh', ['-c', fp+' &'], {detached:true}).unref() or spawn('cmd',...). A second dropper is shipped in lib/telemetry.js (~81KB, disguised as an 'Analytics SDK') containing the same primitives (base64 chunk decode, chmodSync 0755 on 'extensionPath', cp.spawn('/bin/sh', ['-c', filePath+' &'])), with child_process required via the computed string require('child_'+'process'). Requiring or importing this package triggers download-and-execute of an attacker-hosted OS-specific binary. ## Source: ghsa-malware (3d367f5160b47afe3e72f884621b4a8f8946a3a07dfcd5c4c9fbd659c57a2b2a) 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.

pfa-prettier-config@20.9.1

AI Security Review

OSV Corroboration

Decision evidence

Source & flagged code

Source & flagged code

Findings

Source & flagged code