MAL-2026-12836 Malicious code in bigops-tasks-client (npm)

On require() of the package, index.js unconditionally loads compat.js, which downloads a platform-specific binary from obfuscated Cloudflare Workers endpoints (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev) with a DNS TXT chunked-base64 fallback under *.dl.wel1.ru (sdk/ext/pkg/net subdomains). The fetched bytes are written to /tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and detach-spawned via spawn("/bin/sh", ["-c", path+" &"], {detached:true}).unref() (spawn("cmd",…) on Windows). Hostnames and asset paths are runtime-assembled from split fragments (e.g. ["oob","-worker.cf100","-416.wor","ker","s.d","ev"].join("")) to evade static string scanning; drop filenames impersonate benign tooling (dotnet_diag_,.cache_, loader_mac, package.exe, package-arm64). The advertised "tasks client" purpose has no relation to fetching and executing a native binary from Cloudflare Workers infrastructure at import time.

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.