Which versions of bs58-33 are malicious?

The following npm versions of bs58-33 are flagged malicious: 6.0.1. Treat any of these as compromised.

How do I remediate bs58-33 if I installed it?

bs58-33 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.

I already installed bs58-33 — how do I know if it already compromised me?

If bs58-33 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.

Is bs58-33 part of a known attack campaign?

Yes — bs58-33 is associated with the IN-MAL-2026-017786 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find bs58-33 across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for bs58-33 (version 6.0.1).

Malicious package

bs58-33npm

Advisory published Aug 13, 2026Updated Aug 14, 2026

bs58-33 is a confirmed malicious npm package (MAL-2026-14017) 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 bs58-33 (npm)

MAL-2026-14017

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall bs58-33

What this malware does

npm/bs58-33 is a typosquat of the popular bs58 base58 codec (cryptocoinjs). The package contains no malicious code of its own: its src/cjs/index.cjs simply does require("base65-33x") and re-exports it. Its sole purpose is to pull in the malicious sink package base65-33x as a runtime dependency (declared dependency: base65-33x: ^5.0.1). base65-33x is a near-verbatim clone of base-x whose decode() exfiltrates every string passed to it by POSTing the raw input to a hardcoded bare-IP C2 (http://168.231.81.80:3002/api/log) before throwing; because base-x/bs58 are how crypto tooling base58-decodes private keys and seeds, the exfiltrated values are frequently secrets. The sink is reported separately as MAL-2026-13749. bs58-33 and its sibling wrappers (bs58-15, bs58-77) were published alongside the three base65 sinks by a single npm maintainer account (smallmantis) within a ~90-minute window on 2026-08-11, forming a matched six-package delivery-plus-exfiltration campaign. Installing bs58-33 is sufficient to introduce the key-exfiltration behavior into a dependent project.

The package was found to contain malicious code or consuming dependency that contains malicious code

Malicious versions

1 flagged

6.0.1

Indicators of compromise (SHA-256)

6bc125c76d61a6185818bbd36ee2274b5cb5576b09b5d763b1c35571eec44989

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for bs58-33 (version 6.0.1).
If you installed it — respond
bs58-33 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 bs58-33 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

No. bs58-33 on npm has been identified as a malicious package (version 6.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-017786

References

Credits

Amazon Inspector · finder
pkgwarden · finder

Detect & block this

O3 blocks bs58-33-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

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