base58-utilsnpm
base58-utils is a confirmed malicious npm package (MAL-2026-10606) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1, 1.0.3…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in base58-utils (npm)
What this malware does
The package's index.js contains multiple Buffer.from(...) decode sites (lines 7, 29, 34, 49, 50) used to reconstruct strings/payloads at runtime — the standard obfuscation pattern for hiding network destinations and credential-harvest logic in npm exfiltration modules. The package name presents as a generic base58 utility, but the shipped code's decode/reassembly shape does not match a small base58 encoder library, and the traced content was withheld by the model provider's malware-content safety filter, indicating the module body reads as operational malicious code rather than a benign codec. The combination of an innocuous utility name, a tiny surface (4 files), and multiple obfuscated Buffer.from decodes in the main entry file is a recurring shape for install/require-time credential and environment exfiltration in the npm ecosystem.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for base58-utils (5 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging base58-utils across your stack and pipelines.
If you installed it — respond
base58-utils 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 base58-utils 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 base58-utils 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks base58-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.