{"id":"MAL-2026-17565","summary":"Malicious code in typesens (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (3ded39f31b2c2d4d73e0b576ab862c9ed90688153a43c359dae5b26854ad8738)\npackage.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.\n","modified":"2026-10-05T04:15:05.707936162Z","published":"2026-10-05T03:37:54Z","database_specific":{"malicious-packages-origins":[{"import_time":"2026-10-05T03:57:39.903873807Z","modified_time":"2026-10-05T03:37:54Z","sha256":"3ded39f31b2c2d4d73e0b576ab862c9ed90688153a43c359dae5b26854ad8738","source":"amazon-inspector","versions":["1.0.0"],"id":"IN-MAL-2026-021028"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/typesens/v/1.0.0"}],"affected":[{"package":{"name":"typesens","ecosystem":"npm","purl":"pkg:npm/typesens"},"versions":["1.0.0"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"path":"package.json","sha256":"cd88b3bbfe95a13ba12a8a7517f1fb377268f1f7cb5a89e6d776cfde795f83d0","tlsh":"42e0d81389985e5314f8e7a1ad744612b1510f1f11714d0770fb015c8b669a7109fbad"},{"sha256":"89a31ec0719b2137938c892385823ffb993d2d903e1fdfe17b246ba88531609a","tlsh":"daf4f034658a68abb63bcafeace6c72935147c053040606c35deb6581bfdcd15bda0f8","path":"4444.vbs"},{"tlsh":"3c3100444c23e37935b1e31bbc90b092e7f4915c0aa60c51b9aa835e1315f62fb7f84e","path":"readme.md","sha256":"11f2ec1d479385714632f19967af06a5273b66baf7ffab8c9f9e400092735026"}],"package_integrity":[{"hashes":{"sha1":"4fedf17b5de20a106ccf65f4c71696adeeaa5569","sha512_sri":"sha512-61uestwaxCTDLsKJVBZK01RFSeBmrt9Ly9UEisavuicw0xU811gPCdc9Nq9MGPEoyGzFFxugME+FNisieJ+9BQ=="},"filename":"typesens-1.0.0.tgz"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/typesens/MAL-2026-17565.json"}}],"schema_version":"1.9.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}