🛡️ MAL-2026-12035 — bigops-auth-utils

Malicious code in bigops-auth-utils (npm)

Source: amazon-inspector

[email protected] executes an install-time binary dropper on any require/import of the package. index.js top-level runs require('./setup'), which selects an OS/arch-specific asset path and downloads a binary over HTTPS from one of three string-split-obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev) with a DNS-TXT covert-channel fallback that reassembles base64-encoded chunks from sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under a disguising name (.cache_<hex> on POSIX, dotnet_diag_<hex>.exe on Windows), chmod 0755, and spawned detached via /bin/sh -c... & or cmd.exe /c start /b. A TTL marker suppresses re-execution and env-var opt-out flags are named to resemble telemetry toggles. A second copy of the same drop-and-spawn logic is duplicated inside lib/telemetry.js framed as an 'Analytics SDK', with require("child_" + "process"), fs["chmod" + "Sync"], and cp.spawn('/bin/sh', ['-c', filePath + ' &']) using string concatenation to evade static matching. Host construction via array-join splitting, cover-story framing, telemetry-shaped opt-out names, DNS covert-channel fallback, and duplicated execution paths are all evasion signals characteristic of a supply-chain dropper, not a build helper.