---
id: "MAL-2026-18186"
kind: "package"
aliases: ["MAL-2026-18186"]
title: "Malicious code in net-codec-testmetest (npm)"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "net-codec-testmetest", "fixed": [], "affected": "= 1.0.1", "ecosystem": "npm"}]
ecosystems: ["npm"]
tags: ["malicious", "package"]
not_affected_if: []
published_at: "2026-10-22T06:11:48+00:00"
first_seen_at: "2026-10-26T20:51:49+00:00"
updated_at: "2026-10-26T21:05:48+00:00"
sources: [{"source": "osv-malicious", "url": "https://osv.dev/vulnerability/MAL-2026-18186", "first_seen_at": "2026-10-26T20:51:49+00:00"}]
---

# Malicious code in net-codec-testmetest (npm)

## Affected

- npm:net-codec-testmetest affected = 1.0.1 fixed ?

## Timeline

- 2026-10-26T20:51:49+00:00 osv-malicious https://osv.dev/vulnerability/MAL-2026-18186

## From the sources

---
_-= Per source details. Do not edit below this line.=-_

## Source: amazon-inspector (7bf1dbafca56ccfcb849f9ebb80b7a1cdf42007fd12618492620e0f7660476b2)
The package has no native source files but ships a binding.gyp whose sole target is type:'none' and whose sources array uses GYP command expansion (`<!(env node index.js...)`) to execute index.js during `node-gyp rebuild`, which npm invokes automatically whenever a binding.gyp is present. index.js is a Caesar-cipher-obfuscated IIFE whose decoded body imports node:crypto, reads the shipped data.bin blob, AES-128-GCM-decrypts it with hardcoded key/iv/aad, brotli-decompresses the result into a temporary file, and spawns that file under the Bun runtime (declared as the package's only dependency). The combination — binding.gyp with no native sources used purely as an install-time execution smuggler, an obfuscated eval-based loader, and an opaque encrypted payload executed under an alternate runtime — is a packed dropper with no legitimate function for a stated utility library.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_