MAL-2026-12667 Malicious code in csc-csc-core (npm)
Malicious package
Published
MAL-2026-12667 is a malicious package: csc-csc-core (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-2026-12667/ (Markdown: https://insights.sbomify.com/MAL-2026-12667/index.md)
- Package
- csc-csc-core
- Registry
- npm
What is MAL-2026-12667?
MAL-2026-12667 is a malicious package in csc-csc-core, published on 5 Aug 2026.
Official description
On require of csc-csc-core, index.js loads init.js which downloads a platform-specific binary from string-split obfuscated Cloudflare Workers hostnames (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev) with a DNS TXT chunked fallback via *.dl.wel1.ru subdomains, writes it to /var/tmp or %TEMP% under a disguised name (e.g..cache<hex>, dotnet_diag_<hex>.exe), chmods 0755, and spawns it detached via cp.spawn('/bin/sh',['-c', fp+' &'],{detached:true}).unref(). C2 hostnames and resolver domains are assembled at runtime from arrays of fragments to defeat static scanners. A /tmp cooldown marker and DO_NOT_TRACK opt-out are used to evade sandboxes. The README advertises the package as a 'base framework module' with no such behavior.
What should I do about MAL-2026-12667?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.