# MAL-2026-16379: Malicious code in @user-services/web-components (npm)


- **Type:** Malicious package
- **Package:** `@user-services/web-components` (npm)
- **Published:** 22 Sep 2026
- **Also known as:** GHSA-f3g4-6hpx-9mcq

## What is MAL-2026-16379?

MAL-2026-16379 is a malicious package in @user-services/web-components, published on 22 Sep 2026. 

### Official description

@user-services/web-components@9.9.10 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`, `eng@user-services.dev`) are generic and consistent with a dependency-confusion lure aimed at organisations with an internal `@user-services/*` scope.

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.

## What should I do about MAL-2026-16379?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-16379 is a malicious package: @user-services/web-components (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-16379/ (Markdown: https://insights.sbomify.com/MAL-2026-16379/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-16379

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-16379/
Summaries are generated and may contain mistakes; the official description above is the record.