api-nebulanpm

The package declares "preinstall": "node preinstall.cjs" in package.json, and preinstall.cjs is a single-line ~187 KB Function("pbeIUC", "…") invocation implementing a custom PRNG plus string-table decoder (numeric constant table, printable-charset string table UclPgF, a Bob-Jenkins-style mixer, and a decoder that reconstructs strings via modular arithmetic against UclPgF.charCodeAt(...)). The file contains no readable logic — its entire payload is an opaque blob that is decoded and handed to the JS engine during npm install. String fragments visible pre-decoding (e.g. F.kI, [email protected], vCpP.BB/.i+gUAKa) are placeholder-shaped and only resolve to real hosts/commands after runtime decoding, so the actual install-time behavior and any network destinations are hidden from static inspection. The wrapper module (nebula.js) and package.json declare no native build step, no compilation, and no other legitimate reason for a 187 KB obfuscated preinstall script. This is the canonical obfuscated npm preinstall dropper shape: arbitrary attacker-authored code executes on every installer's machine at npm install time, with intent to evade review deliberately concealed by the string-table + Function-eval loader.

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.