MAL-2026-13759 Malicious code in bs58-12 (npm)

Package bs58-12 presents itself as the popular bs58 base58 library (README copied from bs58, advertising npm i --save bs58) but its own code is a thin wrapper: index.js does require("base65-12x") and the sole declared runtime dependency is base65-12x at ^5.0.1, a name resembling the base-x library the real bs58 uses. The package under analysis contains no exfiltration, credential access, install/import-time destructive action, or lifecycle scripts; the only installer-facing behavior is pulling in base65-12x as a dependency. Whether installing bs58-12 causes harm depends on the code shipped by base65-12x, which is a separate package not analyzed here.

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.