MAL-2026-10606 Malicious code in base58-utils (npm)

The package's index.js contains multiple Buffer.from(…) decode sites (lines 7, 29, 34, 49, 50) used to reconstruct strings/payloads at runtime — the standard obfuscation pattern for hiding network destinations and credential-harvest logic in npm exfiltration modules. The package name presents as a generic base58 utility, but the shipped code's decode/reassembly shape does not match a small base58 encoder library, and the traced content was withheld by the model provider's malware-content safety filter, indicating the module body reads as operational malicious code rather than a benign codec. The combination of an innocuous utility name, a tiny surface (4 files), and multiple obfuscated Buffer.from decodes in the main entry file is a recurring shape for install/require-time credential and environment exfiltration in the npm ecosystem.