Malicious code in monte-md-baileys (npm)
Published Sources: OSV (Schadpakete)
- Malicious package
What is affected, what to do
Uninstall the package, isolate affected environments and rotate credentials that were available during installation.
Not sure whether and how you are affected? Ask a question about this vulnerability
Malicious package
npmmonte-md-baileys
“monte-md-baileys” is registered as malicious in the npm repository. Anyone who installed the package should uninstall it immediately, isolate affected environments and rotate credentials that were present during installation.
Affected versions (1)
- 1.0.0
purl: pkg:npm/monte-md-baileys
Sources (1)
amazon-inspector
IN-MAL-2026-021992Versions from this source: 1.0.0
sha256: 489128924ea1bbd77b6e22bb1e8e2457b3e8c2c97caceb78d5fa3a029cde5104
The OSSF `malicious-packages` namespace lists packages flagged as malicious by static analysis or sandbox detonation. An entry here is a confirmed finding, not a suspicion.
Metrics
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Priority
No value is available for this vulnerability.
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CVSS v3
No value is available for this vulnerability.
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EPSS score
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Show all metrics
- Severity
- High
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 30.00 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
This package is part of a large family (100+ identified as of September 2026) of near-identical
forks of the Baileys WhatsApp Web library that inject a covert channel-subscription action into
the WhatsApp socket layer. On connect, the injected code issues an authenticated w:mex FOLLOW
query (query_id 7871414976211147) against one or more attacker-chosen WhatsApp Channel/Newsletter
JIDs, using the installer's own authenticated WhatsApp session -- silently subscribing the
victim's account to channels it never asked to join.
The target JID(s) are hidden from casual source review via one of several obfuscation techniques observed across the family: a plain string literal, base64 encoding, base64+XOR, or a char-code array reconstructed at runtime. Some variants instead fetch a mutable, attacker-controlled remote JSON/JS list of target JIDs from GitHub or another host at runtime, letting the target list change after installation without a new npm publish. Every sample in the family shares the same underlying mechanism (a wrapped/patched socket-connect routine that fires the FOLLOW query some seconds after connect), even though the package name, JID value(s), and obfuscation/delivery method differ per fork.
The malicious action abuses the installer's own authenticated WhatsApp session to gain reach and subscribers for attacker-controlled channels; it does not exfiltrate credentials, establish persistence, or execute arbitrary remote code.
Affected package: monte-md-baileys (npm), version(s): 1.0.0.
-= Per source details. Do not edit below this line.=-
Source: amazon-inspector (489128924ea1bbd77b6e22bb1e8e2457b3e8c2c97caceb78d5fa3a029cde5104)
monte-md-baileys is a fork of the Baileys WhatsApp library. In lib/Socket/newsletter.js, a ws.on('open') handler silently issues a newsletter FOLLOW query for a hardcoded JID (120363407598531220@newsletter) one second after the WhatsApp WebSocket connects, causing the installer's authenticated WhatsApp session to auto-subscribe to the maintainer's channel. The behavior is not disclosed in the README and fires on every socket connect. No credential exfiltration, remote code execution, filesystem persistence, or environment scraping is observed; the covert side-effect is confined to a reach-padding action performed with the installer's WhatsApp identity.