mal-2026-17452
Vulnerability from ossf_malicious_packages
This package is a fork of the Baileys WhatsApp Web library (npm) and belongs to the "PhantomSub" family described by OX Security in September 2026: the publisher injected code that, without the installer asking, uses the installer's own authenticated WhatsApp session to subscribe that account to WhatsApp Channels (newsletters) the publisher chose, by sending the WhatsApp w:mex FOLLOW query (query_id 7871414976211147) for each target channel JID.
package/lib/Socket/newsletter.js lines 62-99 define AUTO_FOLLOW_JIDS, three base64 strings decoded with Buffer.from(..., "base64"), and when the connection opens (line 97) schedule a FOLLOW query for each, 90 seconds apart (cited line 85: await newsletterWMexQuery(jid, QueryIds.FOLLOW);). Decoded JIDs: 120363400505489366@newsletter, 120363430764800148@newsletter and 120363387182851100@newsletter. There is no opt-out and the behavior is not documented. The npm maintainer account (xzv-expzc) also publishes prastzy.
Line numbers refer to version 2.0.0; the same code is present in every published version listed under affected.
Static review of the published tarball(s) found no code that sends WhatsApp credentials or session keys off-host, no install-time payload (the only install hook is Baileys' stock Node.js version check in engine-requirements.js), and no persistence; the payload runs when an application creates a WhatsApp socket with the library. The harm is the covert use of the victim's account to inflate the publisher's channel subscribers.
SHA-256 of the published npm tarball(s): 1.0.0: 55a081ebf3ac419742490d3e1b2425ae56cfae323d1f8a64f4758515fbe83bda; 2.0.0: 2e2befe5201e5a488f4e9253542630805500d210007760f09f9e9bbaac98934a.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "xcvrenzcompany"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "SEMVER"
}
],
"versions": [
"1.0.0",
"2.0.0"
]
}
],
"credits": [
{
"contact": [
"https://github.com/jaym2026"
],
"name": "Rising Sun Solutions LLC",
"type": "FINDER"
}
],
"database_specific": {
"iocs": {
"files": [
{
"digests": {
"sha256": "be5af2eac1d0d405c2bbf1ec1fd57f96695ddf5bd7ce2b5d3117017bfa608ba8"
},
"note": "File containing the injected WhatsApp Channel follow code.",
"paths": [
"package/lib/Socket/newsletter.js"
],
"source": "PACKAGE_ARCHIVE"
}
]
}
},
"details": "This package is a fork of the Baileys WhatsApp Web library (npm) and belongs to the \"PhantomSub\" family described by OX Security in September 2026: the publisher injected code that, without the installer asking, uses the installer\u0027s own authenticated WhatsApp session to subscribe that account to WhatsApp Channels (newsletters) the publisher chose, by sending the WhatsApp `w:mex` FOLLOW query (query_id 7871414976211147) for each target channel JID.\n\n`package/lib/Socket/newsletter.js` lines 62-99 define `AUTO_FOLLOW_JIDS`, three base64 strings decoded with `Buffer.from(..., \"base64\")`, and when the connection opens (line 97) schedule a FOLLOW query for each, 90 seconds apart (cited line 85: `await newsletterWMexQuery(jid, QueryIds.FOLLOW);`). Decoded JIDs: `120363400505489366@newsletter`, `120363430764800148@newsletter` and `120363387182851100@newsletter`. There is no opt-out and the behavior is not documented. The npm maintainer account (`xzv-expzc`) also publishes `prastzy`.\n\nLine numbers refer to version 2.0.0; the same code is present in every published version listed under `affected`.\n\nStatic review of the published tarball(s) found no code that sends WhatsApp credentials or session keys off-host, no install-time payload (the only install hook is Baileys\u0027 stock Node.js version check in `engine-requirements.js`), and no persistence; the payload runs when an application creates a WhatsApp socket with the library. The harm is the covert use of the victim\u0027s account to inflate the publisher\u0027s channel subscribers.\n\nSHA-256 of the published npm tarball(s): 1.0.0: `55a081ebf3ac419742490d3e1b2425ae56cfae323d1f8a64f4758515fbe83bda`; 2.0.0: `2e2befe5201e5a488f4e9253542630805500d210007760f09f9e9bbaac98934a`.",
"id": "MAL-2026-17452",
"modified": "2026-10-01T23:05:37Z",
"references": [
{
"type": "ARTICLE",
"url": "https://www.ox.security/blog/phantomsub-malicious-npm-campaign-secretly-adds-users-to-whatsapp-spam-channels/"
},
{
"type": "PACKAGE",
"url": "https://www.npmjs.com/package/xcvrenzcompany"
}
],
"schema_version": "1.7.4",
"summary": "Malicious code in xcvrenzcompany (npm)"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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