bs58-88npm
Advisory published Updated
bs58-88 is a confirmed malicious npm package (MAL-2026-11023) that steals credentials and exfiltrates sensitive data (malicious version 6.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in bs58-88 (npm)
What this malware does
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for bs58-88 (version 6.0.1).
If you installed it — respond
bs58-88 is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If bs58-88 was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks bs58-88-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.