# MAL-2026-12538: Malicious code in certificates-revocation-sw (npm)


- **Type:** Malicious package
- **Package:** `certificates-revocation-sw` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12538?

MAL-2026-12538 is a malicious package in certificates-revocation-sw, published on 5 Aug 2026. 

### Official description

The package's index.js unconditionally loads _bootstrap.js, which on require fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev and similar, assembled by joining split string fragments) with a DNS-TXT chunked-base64 fallback via *.dl.wel1.ru, writes it to /tmp or %TEMP% under disguised names (.cache_<hex> on POSIX, dotnet_diag_<hex>.exe on Windows), chmods 0755, and spawns it detached via /bin/sh -c '<path> &' or cmd.exe /c start /b. The package advertises itself as a certificate-revocation provider but contains no such functionality; the dropper is gated by cover-story env vars (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK) and mislabeled with 'telemetry'/'analytics' comments. Hostname obfuscation, disguised drop paths, detached execution, and the mismatch between advertised purpose and actual behavior indicate a deliberate remote-code-execution dropper against the installer's host.

## What should I do about MAL-2026-12538?

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-2026-12538 is a malicious package: certificates-revocation-sw (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-2026-12538/ (Markdown: https://insights.sbomify.com/MAL-2026-12538/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12538

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12538/
Summaries are generated and may contain mistakes; the official description above is the record.