@arv-bedrock/auth@1.1.8: Malicious npm security report (Block)

AI Security Review

scanned 11d ago · by lpm-firewall-ai

npm installation executes setup.mjs, which obtains a Bun runtime and runs the obfuscated math_init.js. That payload contains fetched-content eval and credential/token discovery logic.

Static reason

One or more suspicious static signals were detected.; source matched previously finalized malicious package; routed for review

Trigger

npm preinstall

Impact

Arbitrary remote code execution and possible theft of developer credentials.

Mechanism

remote bootstrap and obfuscated credential-harvesting payload execution

Attack narrative

Installing the package invokes setup.mjs. It downloads and executes Bun solely to run an obfuscated payload; that payload fetches text and evaluates it, and contains token/credential discovery and upload logic. This is unrelated to the published OAuth helper and gives a remote actor install-time code execution.

Rationale

The preinstall bootstrap deliberately runs an obfuscated, dynamically evaluated payload with credential-handling code. The benign dist library does not justify this installation behavior.

Evidence

package.jsonsetup.mjsmath_init.jsdist/cjs/auth.js

Network endpoints1

github.com/oven-sh/bun/releases/download/bun-v1.3.13/

Decision evidence

public snapshot

AI called this Malicious at 99.0% confidence as Malware with low false-positive risk.

Evidence for block

package.json runs `node setup.mjs` as preinstall.
setup.mjs downloads Bun from GitHub and executes math_init.js during install.
math_init.js is heavily obfuscated and contains runtime `eval` of fetched response content.
math_init.js includes credential/provider discovery and GitHub-token handling logic.
The install path executes code absent from the declared dist auth library.

Evidence against

dist/cjs/auth.js is a conventional browser OAuth token helper.
No benign package function requires an obfuscated install-time Bun bootstrap.

Behavioral surface

Source

ChildProcessEvalFilesystemNetworkShell

Supply chain

HighEntropyStringsMinifiedUrlStrings

ManifestNo manifest risk signals triggered.

scanned 6 file(s), 740 KB of source, external domains: github.com

Source & flagged code

4 flagged

package.jsonView file

•scripts.preinstall = node setup.mjs

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

math_init.jsView file

1// @bun @bun-cjs L2: var MmgoCP,etDiOOB,JqTtnbZ,bc3Kak,ZQmUTyQ,TTUgga,MDX6yrw,h8wMJNB,CabwE2L,x5ErqV;function WV8StW(MmgoCP,etDiOOB,JqTtnbZ){for(JqTtnbZ=0x0;JqTtnbZ<etDiOOB;JqTtnbZ++)MmgoCP.push(MmgoCP...

Low

Eval

Package source references a known benign dynamic code generation pattern.

math_init.jsView on unpkg · L1

setup.mjsView file

1Manifest entrypoint (scripts.preinstall) carries capability families absent from dist/build output: execution+network L1: #!/usr/bin/env node L2: import { execFileSync } from "child_process"; L3: import _0x488df8 from "fs"; L4: import _0x52943e from "https"; L5: import _0x24db8d from "os"; ... L50: function ra() { L51: const _0x51cd53 = process.platform + "-" + process.arch; L52: const _0x3ab5c4 = PM[_0x51cd53]; ... L218: } else if (_0xc0d7d2 === 8) { L219: _0x27994e = _0x548d91.inflateRawSync(_0x5975df); L220: } else {

High

Entrypoint Build Divergence

Manifest entrypoint contains risky behavior absent from dist/build output.

setup.mjsView on unpkg · L1

•matchType = normalized_sha256 matchedPackage = @ornikar/react-native-svg-transformer@1.0.11 matchedPath = setup.mjs matchedIdentity = npm:[redacted]:1.0.11 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

setup.mjsView on unpkg

Source & flagged code

4 flagged · loading source

package.jsonView file

•scripts.preinstall = node setup.mjs

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

math_init.jsView file

1// @bun @bun-cjs L2: var MmgoCP,etDiOOB,JqTtnbZ,bc3Kak,ZQmUTyQ,TTUgga,MDX6yrw,h8wMJNB,CabwE2L,x5ErqV;function WV8StW(MmgoCP,etDiOOB,JqTtnbZ){for(JqTtnbZ=0x0;JqTtnbZ<etDiOOB;JqTtnbZ++)MmgoCP.push(MmgoCP...

Low

Eval

Package source references a known benign dynamic code generation pattern.

math_init.jsView on unpkg · L1

setup.mjsView file

1Manifest entrypoint (scripts.preinstall) carries capability families absent from dist/build output: execution+network L1: #!/usr/bin/env node L2: import { execFileSync } from "child_process"; L3: import _0x488df8 from "fs"; L4: import _0x52943e from "https"; L5: import _0x24db8d from "os"; ... L50: function ra() { L51: const _0x51cd53 = process.platform + "-" + process.arch; L52: const _0x3ab5c4 = PM[_0x51cd53]; ... L218: } else if (_0xc0d7d2 === 8) { L219: _0x27994e = _0x548d91.inflateRawSync(_0x5975df); L220: } else {

Findings

3 High2 Medium5 Low

HighInstall Time Lifecycle Scriptspackage.json

HighEntrypoint Build Divergencesetup.mjs

HighKnown Malware Source Similaritysetup.mjs

MediumNetwork

MediumStructural Risk Force Deep Review

LowScripts Present

LowEvalmath_init.js

LowFilesystem

LowHigh Entropy Strings

LowUrl Strings