sync-externalnpm
Malicious code in sync-external (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
The package ships an obfuscated JavaScript file at shim/index.js using hex-style identifier mangling (_0x391f3f, _0x3eff0a, _0x534564, etc.) characteristic of javascript-obfuscator output. Obfuscation alone is not proof of malicious intent — some publishers obfuscate for anti-tampering or anti-piracy reasons — but it prevents reliable assessment of the file's runtime behavior, and contextual tracing of the obfuscated code path was not available. No concrete evidence of credential exfiltration, install-time fetch-and-execute, silent-relay of caller data, or hardcoded attacker C2 was observed, but the inability to verify what the obfuscated shim does at load/use time leaves the residual risk unresolved. Recommend human review of the de-obfuscated content before trusting this package in a build pipeline.
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
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 sync-external (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging sync-external across your stack and pipelines.
If you installed it — respond
sync-external 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 sync-external 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 sync-external 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 sync-external-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.