-= Per source details. Do not edit below this line.=-
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.
{
"malicious-packages-origins": [
{
"sha256": "b3d53776853d18aabf967b0f1882eb45f2164feedd600eeccc927f496002f5e4",
"source": "amazon-inspector",
"modified_time": "2026-06-19T15:13:09Z",
"versions": [
"1.4.3"
],
"id": "IN-MAL-2026-007079",
"import_time": "2026-06-19T15:41:55.709372876Z"
}
]
}[
{
"name": "Embedded Malicious Code",
"description": "The product contains code that appears to be malicious in nature.",
"cweId": "CWE-506"
}
]
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/@bytemend/mfebus/MAL-2026-6213.json"
{
"evidence_files": [
{
"sha256": "a9a28f2e9f7e0348092682940b3bf63d47a63afc18eb8bfe628e5ddab0d73b47",
"tlsh": "a6449730b3c07c9425479f7b332ef5e5f92e5fa934a8088bd065bc64a6ea915dad0730",
"path": "dist/bootstrap.js"
}
],
"package_integrity": [
{
"hashes": {
"sha512_sri": "sha512-kxFo8/qHEMUTvwCNgrwOB6TyO1Nr3gcggKfk95jqUR5pz8ITygFiCQ3dKYVDs7jJUmgHbtvPCVwfYXvXRlJRkA==",
"sha1": "35d1f3ede98964880c4759a2346ab1f1893c130b"
},
"filename": "mfebus-1.4.3.tgz"
}
]
}