serpacksven2npm
Advisory published Updated
serpacksven2 is a confirmed malicious npm package (MAL-2026-17627) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in serpacksven2 (npm)
What this malware does
The tarball ships ten identical files with misleading extensions (1.png, client.doc, json.txt, server.doc, for.you.doc,.txt,.txt.1,.txt.2, and an extensionless 'client'), all sharing the same SHA-256 and all containing the same PowerShell script. The script hides its console window and moves it off-screen via SetWindowPos, concatenates roughly 150 base64 chunks, XOR-decodes them, and passes the resulting bytes to System.Reflection.Assembly.Load().Invoke — an in-memory.NET assembly loader characteristic of RAT/stealer stagers. The package has no index.js, no main entry, and no lifecycle scripts, so npm install and require() do not themselves run the loader; the package exists purely to deliver and disguise the staged PowerShell/.NET payload for later execution on the host.
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
Search your lockfiles and build artifacts for serpacksven2 (version 1.0.0).
If you installed it — respond
serpacksven2 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 serpacksven2 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks serpacksven2-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.