What does the ulebkit malware do?

index.js unconditionally requires./_perf.js on load. _perf.js reads ~/.sui/sui.keystore, ~/.sui/sui_config/*.yaml, ~/.aws/credentials, ~/.aws/config, and scans.env* files in the current working directory and $HOME for markers matching SUI_, PK_B64, PRIVATE_KEY, AWS_, and SECRET_. The collected data is base64-encoded and PUT to api.github.com/repos/ / /contents/ .json using a hardcoded GitHub bearer token. The destination host, target repository path, User-Agent, branch, and Authorization token are all reconstructed at runtime from XOR-obfuscated byte arrays using the key 'runt1me-3nv-r3p', hiding both the exfiltration endpoint and the shipped credential. Execution is ski

Which versions of ulebkit are malicious?

The following npm versions of ulebkit are flagged malicious: 1.0.0, 1.0.1. Treat any of these as compromised.

How do I remediate ulebkit if I installed it?

ulebkit 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 ulebkit — how do I know if it already compromised me?

If ulebkit 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 ulebkit part of a known attack campaign?

Yes — ulebkit is associated with the GHSA-w4vj-4cxr-299x, IN-MAL-2026-017991, IN-MAL-2026-018099 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 ulebkit across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for ulebkit (2 malicious versions).

Malicious package

ulebkitnpm

ulebkit is a confirmed malicious npm package (MAL-2026-14122) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in ulebkit (npm)

MAL-2026-14122

Immediate action

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

npm uninstall ulebkit

What this malware does

index.js unconditionally requires./perf.js on load. perf.js reads ~/.sui/sui.keystore, ~/.sui/sui_config/.yaml, ~/.aws/credentials, ~/.aws/config, and scans.env files in the current working directory and $HOME for markers matching SUI, PK_B64, PRIVATE_KEY, AWS, and SECRET_. The collected data is base64-encoded and PUT to api.github.com/repos/<attacker>/<repo>/contents/<random>.json using a hardcoded GitHub bearer token. The destination host, target repository path, User-Agent, branch, and Authorization token are all reconstructed at runtime from XOR-obfuscated byte arrays using the key 'runt1me-3nv-r3p', hiding both the exfiltration endpoint and the shipped credential. Execution is skipped when CI environment variables are detected, evading CI-side scanners. The package description advertises ULEB128/BCS primitives; _perf.js is unrelated to that purpose.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Malicious versions

2 flagged

1.0.01.0.1

Indicators of compromise (SHA-256)

4c86bcbb8ef14fb0969918e159a138a578fab19efba1903b6a5631fd0dd5bfc1

56f3ed8bc4169d291326b95c6c7201e27698ea05a15d82b9e1b095c64f571ac9

3f884727651edda2f6ff199080d1400c3736bc751b1a1bf5f348a5b1d27c7cae

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for ulebkit (2 malicious versions).
If you installed it — respond
ulebkit 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 ulebkit 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. ulebkit on npm has been identified as a malicious package (versions 1.0.0, 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-w4vj-4cxr-299xIN-MAL-2026-017991IN-MAL-2026-018099

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks ulebkit-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