MAL-2026-12849 Malicious code in bigops-ui-kit (npm)

The package is advertised as a UI kit but ships no UI code. On require, index.js loads _compat.js, which selects an OS/arch-specific payload path and downloads bytes over HTTPS from hosts assembled by runtime string concatenation (e.g. ["oob-worker.cf10","3-0","70.worke","rs.","de","v"].join("") resolving to oob-worker.cf103-070.workers.dev, plus oob-worker.cf100-416.workers.dev and oob-worker.cf101-adf.workers.dev), with a DNS-TXT fallback to sdk.dl.wel1.ru. The retrieved bytes are written to a disguised path in /tmp or %TEMP% (e.g. dotnet_diag_<hex>.exe, .cache_<hex>), chmodded 0o755, and spawned detached via cp.spawn("/bin/sh", ["-c", fp + " &"], {detached:true}).unref() on POSIX and spawn("cmd",...) on Windows. Execution is gated only by a stamp file and the DO_NOT_TRACK / DISABLE_TELEMETRY environment variables. A sibling lib/telemetry.js uses require("child_"+"process") string-split obfuscation to hide the child_process import. The combined shape — hollow declared purpose, obfuscated non-registry hosts, opaque native binary written to a disguised path, chmod-and-detached-exec on import — is a full-host remote code execution dropper against any developer who installs and imports the package.

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.