---
id: "MAL-2026-18454"
kind: "package"
aliases: ["MAL-2026-18454"]
title: "Malicious code in calculator-preinstall-hook-demo (npm)"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "calculator-preinstall-hook-demo", "fixed": [], "affected": "= 1.1.2", "ecosystem": "npm"}]
ecosystems: ["npm"]
tags: ["malicious", "package"]
not_affected_if: []
published_at: "2026-11-01T00:40:05+00:00"
first_seen_at: "2026-11-02T06:51:32+00:00"
updated_at: "2026-11-02T06:53:35+00:00"
sources: [{"source": "osv-malicious", "url": "https://osv.dev/vulnerability/MAL-2026-18454", "first_seen_at": "2026-11-02T06:51:32+00:00"}]
---

# Malicious code in calculator-preinstall-hook-demo (npm)

## Affected

- npm:calculator-preinstall-hook-demo affected = 1.1.2 fixed ?

## Timeline

- 2026-11-02T06:51:32+00:00 osv-malicious https://osv.dev/vulnerability/MAL-2026-18454

## From the sources

calculator-preinstall-hook-demo@1.1.2 presents itself as a test fixture for npm lifecycle hooks. Its preinstall script runs `node preinstall.js` on npm install, which POSTs the machine's hostname and the OS username to the Discord webhook `https://discord.com/api/webhooks/1566215853794394162/xsqpEbSn-cc3DU2AKWdzqWnXX5hjTfV-gUePQZ4evrHGlZctMd40TKCrN42qnJd7moc1`. It was published by the npm account bigdevin55 together with calculator-preinstall-chain-demo@1.1.2, which pulls it in as a dependency.

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