sso-tramvai-lib-rolesnpm
sso-tramvai-lib-roles is a confirmed malicious npm package (MAL-2026-12442) that executes malicious code on install (malicious version 20.8.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in sso-tramvai-lib-roles (npm)
What this malware does
The package advertises itself as an SSO roles library but on require() loads runtime.js, which detects the host platform, downloads an unsigned binary from obfuscated Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev — assembled via array-joined string fragments), with a DNS TXT-record fallback channel over subdomains of dl.well1.site (base64-reassembled chunks under c.<domain> and N.<domain>). The fetched bytes are written to disk under deceptive names (dotnet_diag.exe,.cache_), chmod'd 0755, and executed detached via cmd.exe /c start /b on Windows or /bin/sh -c on Unix, with no hash or signature verification. A second parallel dropper module lib/telemetry.js (~81 KB) ships in the tarball framed as an 'analytics SDK' and contains the same base64-decode + chmod 0755 + sh -c <file> & pattern; it is not referenced from index.js in this version but is present in the published artifact. The package name resembles a Tramvai-family library; the code has no relationship to SSO or role management.
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
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for sso-tramvai-lib-roles (version 20.8.3). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging sso-tramvai-lib-roles across your stack and pipelines.
If you installed it — respond
Remove sso-tramvai-lib-roles from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If sso-tramvai-lib-roles 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 sso-tramvai-lib-roles 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 sso-tramvai-lib-roles-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.