serpacksvennpm

The tarball contains only package.json and json.txt. The declared main (index.js) is absent, so requiring the package fails — the package is not a functional JS library. json.txt is a heavily obfuscated PowerShell script that hides the console window via GetConsoleWindow + ShowWindow(0) and SetWindowPos to offscreen coordinates (-32000,-32000), performs randomized sleeps and junk-variable noise, concatenates ~150 base64 string fragments into one buffer, base64-decodes and XOR-decrypts it with key 89, then reflectively loads the decoded bytes as a.NET assembly through a runtime-constructed [System.Reflection.Assembly]::Load invocation whose type and method names are rebuilt from char-code arithmetic. The in-memory.NET payload is opaque and attacker-controlled. The package has no lifecycle scripts, so installation alone does not execute json.txt, but any environment that invokes the shipped file via powershell will run the embedded payload. The disguised.txt extension, cover-story main entry, console-hiding, anti-analysis obfuscation, and reflective load of an opaque buffer are the signature of a malware staging artifact rather than legitimate tooling.

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.