Which versions of bs58-15 are malicious?

The following npm versions of bs58-15 are flagged malicious: 6.0.1. Treat any of these as compromised.

How do I remediate bs58-15 if I installed it?

bs58-15 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 bs58-15 — how do I know if it already compromised me?

If bs58-15 was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is bs58-15 part of a known attack campaign?

Yes — bs58-15 is associated with the IN-MAL-2026-017667 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 bs58-15 across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for bs58-15 (version 6.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging bs58-15 across your stack and pipelines.

Malicious package

bs58-15npm

bs58-15 is a confirmed malicious npm package (MAL-2026-13964) 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 bs58-15 (npm)

MAL-2026-13964

Immediate action

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

npm uninstall bs58-15

What this malware does

npm/bs58-15 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("base65-15x") and re-exports it. Its sole purpose is to pull in the malicious sink package base65-15x as a runtime dependency (declared dependency: base65-15x: ^5.0.1). base65-15x 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://46.250.253.63:3000/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-2026-13748. bs58-15 and its sibling wrappers (bs58-33, 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 bs58-15 is sufficient to introduce the key-exfiltration behavior into a dependent project.

Package name 'bs58-15' impersonates the widely-used 'bs58' base58 encoding library, and its package.json metadata (repository, homepage, bugs) points at the legitimate cryptocoinjs/bs58 project despite being published by an unrelated author, presenting false provenance. The package's single runtime dependency is 'base65-15x', a lookalike of the legitimate 'base-x' package. The main entry executes require("base65-15x") and immediately invokes the returned value as a function against an alphabet constant on module load, so any consumer that installs bs58-15 and requires it pulls attacker-named dependency code into their dependency graph and executes it at import time.

Malicious versions

1 flagged

6.0.1

Indicators of compromise (SHA-256)

99502d2feb4743e651628a07ca032fa0cc813ff6482cae15d9c2f1fb6fce63c4

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for bs58-15 (version 6.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging bs58-15 across your stack and pipelines.
If you installed it — respond
bs58-15 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 bs58-15 was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks bs58-15 before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. bs58-15 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-2026-017667

References

Credits

Amazon Inspector · finder
pkgwarden · finder

Detect & block this

O3 blocks bs58-15-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

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