MalwarePublished 27 Jun 2026Updated 30 Jun 2026

chai-as-persisted (npm) · Malicious Code

Affects chai-as-persistedSource GCVE Database

Malicious package : remove chai-as-persisted and rotate any secrets on hosts that installed it.

Data as of 30 Jun 2026, 23:56 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-6544

What to do

Remove chai-as-persisted from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
npmchai-as-persisted	Affected =4.2.8 =6.1.9	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

The npm package 'chai-as-persisted' is a malicious typosquatting package impersonating the legitimate 'chai-as-promised' package. Its postinstall script executes attacker-controlled JavaScript by decoding a hidden command-and-control URL and running code fetched from it, resulting in remote code execution (RCE) on the installer's machine. The malicious code runs detached from the install process, maintaining persistence beyond installation. Installing this package fully compromises the affected system, risking exposure of all stored secrets and keys.

Impact

Any system that installs or runs this package is fully compromised due to the execution of attacker-controlled code with full Node.js access. This can lead to unauthorized access, data theft, and persistent backdoors. All secrets and keys stored on the compromised system should be considered exposed and must be rotated immediately. Removing the package does not guarantee removal of all malicious artifacts or backdoors.

Defensive guidance

Remove the 'chai-as-persisted' package immediately from all affected systems. Rotate all secrets and keys that were stored or accessible on the compromised machines using a secure, unaffected environment. Because the attacker gains full control during installation, assume the system is fully compromised and consider rebuilding or thoroughly auditing the environment.

Summary

The 'chai-as-persisted' npm package contains a postinstall script that executes 'index.js', which spawns a detached child process running 'lib/initializeCaller.js'. This module hides a base64-encoded C2 URL in fabricated environment variables to evade detection. At install time, it decodes the URL, sends a POST request to it, and executes the response as JavaScript with full Node.js module access via 'new Function.constructor'. This results in remote code execution on the installer's machine. The package is a deliberate typosquat of 'chai-as-promised' with unrelated malicious code masquerading as a logger middleware.

References

Community reviews

Loading reviews…

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Jun 2026, 23:56 UTC

Technical details

References

Community reviews