MAL-2026-11023 Malicious code in bs58-88 (npm)

Package bs58-88 mimics the popular bs58 base58 encoder: README, keywords, and repository URL match the real bs58, and index.cjs re-exports functionality via require("base65-85x"). The sole runtime dependency base65-85x is itself a name that resembles the legitimate base-x package. The package under review does not contain traced installer-harm behavior (no exfiltration, no install-time fetch-and-execute, no credential access, no lifecycle scripts observed), so the concern is name-confusion plus a look-alike transitive rather than a demonstrated payload in this artifact. Whether base65-85x is itself malicious was not established here; a human reviewer should assess both the name-similarity judgment against bs58/base-x and the trust of the base65-85x dependency before publishing a public advisory.

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.