MAL-2026-18186 Malicious code in net-codec-testmetest (npm)

The package has no native source files but ships a binding.gyp whose sole target is type:'none' and whose sources array uses GYP command expansion (<!(env node index.js...)) to execute index.js during node-gyp rebuild, which npm invokes automatically whenever a binding.gyp is present. index.js is a Caesar-cipher-obfuscated IIFE whose decoded body imports node:crypto, reads the shipped data.bin blob, AES-128-GCM-decrypts it with hardcoded key/iv/aad, brotli-decompresses the result into a temporary file, and spawns that file under the Bun runtime (declared as the package's only dependency). The combination — binding.gyp with no native sources used purely as an install-time execution smuggler, an obfuscated eval-based loader, and an opaque encrypted payload executed under an alternate runtime — is a packed dropper with no legitimate function for a stated utility library.