npm · Malicious package advisory
Malware@achuthvp/postinstall-poc
MAL-2026-5741
Malicious code in @achuthvp/postinstall-poc (npm)
Details
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_-= Per source details. Do not edit below this line.=-_
## Source: amazon-inspector (c3dc0d7b5fc216ae117dda9c492a6bbdff46e49ab53f069c2d525dab001bcdb9)
package.json declares scripts.postinstall = `node postinstall.js`. On every `npm install`, postinstall.js runs `execSync('id')` and POSTs a JSON body containing the `id` output, `os.hostname()`, platform, architecture, `process.cwd()`, and Node version to the hardcoded URL `https://webhook.site/fceebb0d-9f11-4ac0-98db-6f6b3925f7d3` (postinstall.js line 14, exfil call constructed via `https.request` at line 21 with POST at line 24). The behavior is unconditional, undisclosed in the README (`Does nothing much`), and fires on a default install. Although the package self-describes as a POC, the install-time mechanism is identical to an active reconnaissance/exfiltration payload: any developer or CI machine installing this package leaks its identity (uid/gid/groups via `id`, hostname, cwd, platform) to an attacker-readable webhook bin.
## Source: ghsa-malware (e8e170e9a09b3a974051edd563fd5aed8c6adb41a243339229375c85e84d221d)
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Compromised versions (4)
- 1.0.2
- 1.0.3
- 1.0.1
- 1.0.0
Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.