MAL-2026-17439
Malicious code in @developmentyora/baileyss (npm)
Published Oct 16, 2026 · corrected/updated Oct 16, 2026 · evidence confidence medium
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 FOLLOW query (query_id 7871414976211147) for each target channel JID. lines 62-103 (cited line 68: ) run in the body of , so they fire whenever a socket is created: 90 seconds later, and then at 5-second intervals, the code sends FOLLOW queries for four channel JIDs, each stored as a base64 literal decoded with : , , and . There is no opt-out and the behavior is not documented. Line numbers refer to version 1.0.0. 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 ), 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: . --- _-= Per source details. Do not edit below this line.=-_ ## Source: ghsa-malware (61d053d8d7d05715f1099bf3d620177886fda31a4c45f5c21d687b2fcd9abb39) 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.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
MAL-2026-17439 is a unknown public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: @developmentyora/baileyss (1.0.0). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: no CVSS/EPSS yet. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: github, osv. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 16, 2026 · GitHub Advisory Database
Detected
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 FOLLOW query (query_id 787
Oct 16, 2026 · GitHub Advisory Database
Updated
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 FOLLOW query (query_id 787
Affected
- npm @developmentyora/baileyss1.0.0
Sources
- GitHub Advisory DatabasePackage advisoryGHSA-v8xh-mr86-2fpq
GitHub Advisory Database record mirrored by OSV.
github.com - OSV.devPackage advisoryMAL-2026-17439
Malicious code in @developmentyora/baileyss (npm)
osv.dev