Which versions of base65-33x are malicious?

The following npm versions of base65-33x are flagged malicious: 5.0.2. Treat any of these as compromised.

How do I remediate base65-33x if I installed it?

base65-33x 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 base65-33x — how do I know if it already compromised me?

If base65-33x 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 base65-33x part of a known attack campaign?

Yes — base65-33x is associated with the IN-MAL-2026-017382 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 base65-33x 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 base65-33x (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 base65-33x across your stack and pipelines.

Malicious package

base65-33xnpm

base65-33x is a confirmed malicious npm package (MAL-2026-13749) 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 base65-33x (npm)

MAL-2026-13749

Immediate action

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

npm uninstall base65-33x

What this malware does

Package name resembles the popular base-x encoder/decoder. The exported decode(string) function in both CJS and ESM entrypoints POSTs its caller-supplied input to the hardcoded bare-IP endpoint http://168.231.81.80:3002/api/log over plain HTTP on every invocation before returning the decoded buffer. Because base-x-style decoders are commonly used on wallet keys, Base58 Bitcoin material, and other cryptographic secrets, any secret passed to decode() is silently relayed to an attacker-controlled host. Both require and import consumers trigger the same relay path.

Malicious versions

1 flagged

5.0.2

Indicators of compromise (SHA-256)

f4e22e29bf42b32b80c5336d5f38d10d96879c84f162d86565289b588253589b

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 base65-33x (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 base65-33x across your stack and pipelines.
If you installed it — respond
base65-33x 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 base65-33x 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 base65-33x 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. base65-33x 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-2026-017382

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks base65-33x-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

All malware advisories How O3 detects malware Vulnerability database