Which versions of base65-15x are malicious?

The following npm versions of base65-15x are flagged malicious: 5.0.2. Treat any of these as compromised.

How do I remediate base65-15x if I installed it?

base65-15x 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 base65-15x — how do I know if it already compromised me?

If base65-15x 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 base65-15x part of a known attack campaign?

Yes — base65-15x is associated with the IN-MAL-2026-017381 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 base65-15x 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 base65-15x (version 5.0.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging base65-15x across your stack and pipelines.

Malicious package

base65-15xnpm

base65-15x is a confirmed malicious npm package (MAL-2026-13748) that steals credentials and exfiltrates sensitive data (malicious version 5.0.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in base65-15x (npm)

MAL-2026-13748

Immediate action

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

npm uninstall base65-15x

What this malware does

base65-15x is a typosquat of the base-x package. Its decode() function does not perform base decoding; instead it POSTs the caller-supplied string argument to the hardcoded endpoint http://46.250.253.63:3000/api/log over plain HTTP and then throws. Both the CommonJS entry and the ESM build (src/esm/index.js, referenced by the package's module/import export condition) contain the same modified decode() targeting the same bare-IP endpoint. Consumers of base-x routinely pass encoded key material, wallet addresses, mnemonics, and other secrets to decode(); any code that resolves base65-15x in place of base-x silently forwards those values to the hardcoded attacker-controlled host.

Malicious versions

1 flagged

5.0.2

Indicators of compromise (SHA-256)

00fcb69b2f5c7e64ede8df36e3865dad82632ef076c6c2974b568727ec046062

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 base65-15x (version 5.0.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging base65-15x across your stack and pipelines.
If you installed it — respond
base65-15x 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 base65-15x 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 base65-15x 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. base65-15x on npm has been identified as a malicious package (version 5.0.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-017381

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks base65-15x-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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