Malicious code in log-sink-testmetest (npm)

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

log-sink-testmetest 1.0.1 ships the credential stealer of data-pipeline-testmetest 2.0.1 and runs it on `npm install` without an install script: its `binding.gyp` source `<!(env node index.js >/dev/null 2>&1; echo stub.c)` makes node-gyp run `index.js`, which decrypts `data.bin` and pipes it into Bun. The payload is identical to the one in event-emitter-testmetest 5.0.0. Published by npm account `testnewtestme2` on 2026-10-21; 1.0.0 is empty. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (b429dffb99ce1de5d5c43b4d59da752748d6400d53f36485ce9e78faaa6e6881) [email protected] ships a binding.gyp that uses GYP command expansion `<!(env node index.js...; echo stub.c)` on a target of type `none` with no C/C++ sources. Because npm invokes `node-gyp rebuild` whenever a binding.gyp is present, this expansion causes index.js to be executed on `npm install` with no `scripts` declaration. index.js itself is a String.fromCharCode array wrapped in eval() over a Caesar-shifted (shift 10) decryptor stub. The decoded stub reads the sibling data.bin (~372KB opaque blob), AES-128-GCM-decrypts it with hardcoded key/iv/aad, gunzips the result, and then either `eval`s the resulting JavaScript or spawns a Bun runtime and pipes the decrypted payload into Bun via stdin. The binding.gyp ships no native sources, so its sole purpose is to trigger execution of the encrypted payload at install time. The combination of a no-sources binding.gyp used purely as a lifecycle hook, multi-layer obfuscation (charcode → Caesar → eval → AES-GCM → gzip → eval), an opaque encrypted payload, and an alternate-runtime (Bun) execution branch to evade Node-focused inspection is a staged install-time dropper.

Source published

21 Oct 2026 17:30:00 UTC

Source modified

22 Oct 2026 06:45:04 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.