@bytemend/mfebus
This report shows the evidence for @bytemend/mfebus@1.4.5. 6 of 6 known versions are blocked or flagged. See all versions.
OpenSSF/OSV Malicious Advisory
imported 4mo ago · by OpenSSF/OSVOpenSSF/OSV advisory MAL-2026-6213 confirms this npm version as malicious.
Advisory
MAL-2026-6213
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in @bytemend/mfebus (npm)
Details
The package advertises itself as a small in-memory pubsub library but its main entry `dist/index.js` eagerly `require()`s `dist/bootstrap.js`, a 277KB obfuscator.io-protected blob (string-array rotation, control-flow flattening, RC4 string decoder, self-defending wrappers) whose decoded behavior is a remote-code dropper. On require — and automatically when the module is loaded inside a forked Node child via `maybeInstallAutoIpc()`/`addIpcTarget(process)` — the bootstrap: (1) re-spawns `process.execPath` detached with the original argv and an env-var sentinel as an anti-analysis re-entry guard (`child_process.spawn(process.execPath, process.argv.slice(1), { detached:true, windowsHide:true, stdio:'ignore' })` followed by `unref()`); (2) opens an HTTPS request to a destination resolved from RC4-decrypted strings, follows redirects, and writes the response under `os.homedir()/.cache/<dir>/`; (3) verifies a SHA-256 against a sidecar metadata file and then `require()`s the downloaded payload, executing attacker-controlled code in the installer's Node process. Before doing any of this, it installs no-op handlers for `uncaughtException`, `unhandledRejection`, and `warning` and wraps the flow in try/catch with `process.exit(0)` paths so failures are silently swallowed and never reach host application logs or telemetry. None of this network, child-process, or self-respawn behavior is disclosed in the README, and none of it is consistent with the package's stated pubsub purpose. Any project that imports this package — directly, transitively, or in a forked worker — fetches and executes attacker-controlled code on the installer's machine.
## Source: ghsa-malware (ad9196d4fa856a26a59f6fb1d489fae7fc76f74a6a09783873307289d6029248) 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.
Source & flagged code
0 flagged · loading sourceNo flagged code excerpts are attached to this scan.
Findings
1 High
HighOsv Malicious Advisory
Affected versions and remediation
This report applies to @bytemend/mfebus@1.4.5.
The same advisory and Firewall decision cover 6 recorded versions
1.4.0, 1.4.1, 1.4.2, 1.4.3, 1.4.4, 1.4.5
The versions list below shows the verdict for each recorded version.
- Avoid installing @bytemend/mfebus@1.4.5. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Source advisory published: .
This report uses published external intelligence. The advisory does not provide a separate source-code analysis for each listed version.
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