MAL-2026-6502: Malicious code in js-client-node (npm)
The npm package 'js-client-node' version 1.4.0 contains malicious code that exfiltrates environment variables from the installer's project during installation. It uses a postinstall hook to read the .env file at the project root and sends all environment variables, including sensitive data like API keys and credentials, to a remote server. The package disguises itself as a legitimate crypto price fetcher, with a misleading README and package metadata. This results in silent leakage of sensitive information upon installation.
AI Analysis
Technical Summary
The 'js-client-node' npm package version 1.4.0 includes a postinstall script that executes automatically during 'npm install'. This script resolves the project root directory, reads the .env file using dotenv, and sends the full JSON of all environment variables to a remote URL. The URL is obfuscated via a custom base58 decoder with parts split across two source files. Errors during this process are suppressed, so no warnings appear during installation. The package metadata and README are deliberately deceptive to mask the malicious behavior. This causes any developer installing this package to inadvertently leak sensitive environment variables to an attacker-controlled endpoint.
Potential Impact
Sensitive environment variables such as API keys, database credentials, and cloud tokens stored in the .env file of the project are exfiltrated silently to a remote attacker-controlled server during package installation. This can lead to unauthorized access to critical systems and data breaches. The compromise occurs immediately upon installation without user awareness due to error suppression.
Mitigation Recommendations
No official patch or remediation is currently documented. Users should avoid installing version 1.4.0 of 'js-client-node'. Verify package authenticity before installation and prefer trusted sources. Monitor for updates or advisories from the package maintainers or npm registry. Since this is a malicious package, removal and replacement with a legitimate alternative is recommended.
MAL-2026-6502: Malicious code in js-client-node (npm)
Description
The npm package 'js-client-node' version 1.4.0 contains malicious code that exfiltrates environment variables from the installer's project during installation. It uses a postinstall hook to read the .env file at the project root and sends all environment variables, including sensitive data like API keys and credentials, to a remote server. The package disguises itself as a legitimate crypto price fetcher, with a misleading README and package metadata. This results in silent leakage of sensitive information upon installation.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The 'js-client-node' npm package version 1.4.0 includes a postinstall script that executes automatically during 'npm install'. This script resolves the project root directory, reads the .env file using dotenv, and sends the full JSON of all environment variables to a remote URL. The URL is obfuscated via a custom base58 decoder with parts split across two source files. Errors during this process are suppressed, so no warnings appear during installation. The package metadata and README are deliberately deceptive to mask the malicious behavior. This causes any developer installing this package to inadvertently leak sensitive environment variables to an attacker-controlled endpoint.
Potential Impact
Sensitive environment variables such as API keys, database credentials, and cloud tokens stored in the .env file of the project are exfiltrated silently to a remote attacker-controlled server during package installation. This can lead to unauthorized access to critical systems and data breaches. The compromise occurs immediately upon installation without user awareness due to error suppression.
Mitigation Recommendations
No official patch or remediation is currently documented. Users should avoid installing version 1.4.0 of 'js-client-node'. Verify package authenticity before installation and prefer trusted sources. Monitor for updates or advisories from the package maintainers or npm registry. Since this is a malicious package, removal and replacement with a legitimate alternative is recommended.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-6502
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a3ef7c127e9c79719ffdfe0
Added to database: 06/26/2026, 22:05:53 UTC
Last enriched: 06/26/2026, 22:34:44 UTC
Last updated: 06/26/2026, 22:34:44 UTC
Views: 2
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