@user-services/web-componentsnpm
@user-services/web-components is a confirmed malicious npm package (MAL-2026-16379) that steals credentials and exfiltrates sensitive data (malicious version 9.9.10). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @user-services/web-components (npm)
What this malware does
@user-services/[email protected] fires a hidden telemetry probe on both the npm install lifecycle (node index.js) and on every require() of the module. The probe in probe/impl.js reads os.userInfo().username, os.hostname() and the basename of process.cwd(), concatenates them with a prefix uswc and a timestamp into a subdomain of oob.algamil7x.xyz, and issues a dns.resolve4 query — the query name itself is the exfiltration channel, delivering installer identity to the attacker-controlled authoritative nameserver. The exfil pipeline is deliberately hidden from static analysis: supporting modules (b8d6e3.js, c9e7f4.js) reconstruct the strings os, dns, process, userInfo, hostname, cwd, resolve4 and the destination host oob.algamil7x.xyz from String.fromCharCode byte arrays, and load the os and dns core modules via module.constructor._load(...) instead of a static require. The destination host is not the declared homepage and is not documented anywhere in the package. The scope @user-services and its placeholder repository/author metadata (github.com/user-services/web-components, [email protected]) are generic and consistent with a dependency-confusion lure aimed at organisations with an internal @user-services/* scope.
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 @user-services/web-components (version 9.9.10). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @user-services/web-components across your stack and pipelines.
If you installed it — respond
@user-services/web-components 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 @user-services/web-components 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 @user-services/web-components 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 @user-services/web-components-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.