Malicious code in typesens (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (3ded39f31b2c2d4d73e0b576ab862c9ed90688153a43c359dae5b26854ad8738) package.json declares postinstall `wscript.exe 4444.vbs`, which runs automatically on `npm install`. The shipped 4444.vbs (~765 KB) contains a multi-layer decryption chain (AES S-box, ChaCha20-IETF, SHA-256 constants XOR-masked with 0x5A5A5A5A) over ~665 base64 chunks, decodes a payload to %TEMP% as a.dat file, drops a PowerShell loader, and invokes powershell.exe to perform process hollowing on Windows. Function names in the VBS are randomized (PlatformProbeLVI, DeviceCatalogUBYQ, EndpointRegistryRFX) and the `CreateObject` target is XOR-decoded at runtime; a cover-story header labels the file as a 'Verdant Signals Corp Device Telemetry Aggregator'. The advertised library surface — src/index.js is a trivial zod-based email-domain check with no network I/O, and the README claims 'No installation scripts' and describes a 'booking-eligibility' utility — is a decoy contradicting the package.json `files` entry that ships 4444.vbs and the postinstall hook that runs it. The typosquat-shaped name (typesens) reinforces the lure framing.
MAL-2026-17565
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:MAL-2026-17565
typesens
Source reference: /affected/0/package/name
- Affected versions
- 1.0.0
Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"package": {
"name": "typesens",
"purl": "pkg:npm/typesens",
"ecosystem": "npm"
},
"versions": [
"1.0.0"
],
"database_specific": {
"cwes": [
{
"name": "Embedded Malicious Code",
"cweId": "CWE-506",
"description": "The product contains code that appears to be malicious in nature."
}
],
"source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/typesens/MAL-2026-17565.json",
"indicators": {
"evidence_files": [
{
"path": "package.json",
"tlsh": "42e0d81389985e5314f8e7a1ad744612b1510f1f11714d0770fb015c8b669a7109fbad",
"sha256": "cd88b3bbfe95a13ba12a8a7517f1fb377268f1f7cb5a89e6d776cfde795f83d0"
},
{
"path": "4444.vbs",
"tlsh": "daf4f034658a68abb63bcafeace6c72935147c053040606c35deb6581bfdcd15bda0f8",
"sha256": "89a31ec0719b2137938c892385823ffb993d2d903e1fdfe17b246ba88531609a"
},
{
"path": "readme.md",
"tlsh": "3c3100444c23e37935b1e31bbc90b092e7f4915c0aa60c51b9aa835e1315f62fb7f84e",
"sha256": "11f2ec1d479385714632f19967af06a5273b66baf7ffab8c9f9e400092735026"
}
],
"package_integrity": [
{
"hashes": {
"sha1": "4fedf17b5de20a106ccf65f4c71696adeeaa5569",
"sha512_sri": "sha512-61uestwaxCTDLsKJVBZK01RFSeBmrt9Ly9UEisavuicw0xU811gPCdc9Nq9MGPEoyGzFFxugME+FNisieJ+9BQ=="
},
"filename": "typesens-1.0.0.tgz"
}
]
}
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #83620 · Revision 1
- Added to Heist Feed
- Publisher date