MAL-2026-12624 Malicious code in claims-historical-claims-api-adapters (npm)

index.js unconditionally requires loader.js on module load. loader.js reconstructs remote hostnames from split string fragments (e.g. ["oob-worker.cf99-9b","3.wo","rk","ers.d","ev"].join("")) to yield oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, and oob-worker.cf102-baf.workers.dev, with a DNS-TXT chunked-base64 fallback via sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. Based on process.platform, a binary is downloaded over HTTPS, written to /var/tmp or %TEMP% under a disguised name (.cache<rand> or dotnet_diag<rand>.exe), chmod'd 0755, and spawned detached via cp.spawn("/bin/sh",["-c", fp+" &"],{detached:true,stdio:"ignore"}).unref(). A parallel dropper module lib/telemetry.js, framed as an 'Analytics SDK', ships the same fetch-write-exec shape with require("child_"+"process") and fs["chmod"+"Sync"] dynamic property assembly. The obfuscation of host strings and module names, disguised filenames, and detached background execution are consistent with a canonical import-time RCE dropper.