🛡️ MAL-2026-12620 — claims-get-error-string

Malicious code in claims-get-error-string (npm)

Source: amazon-inspector

On require(), index.js loads _ext.js which downloads a platform-specific binary from a set of hardcoded Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev) assembled by string-splitting to evade static matching. The downloaded bytes are written to /var/tmp or %TEMP% under innocuous names (.cache_<rnd> on POSIX, dotnet_diag_<rnd>.exe on Windows), chmod 0755 is applied, and the binary is spawned detached via /bin/sh -c '<path> &' or cmd. A DNS-TXT covert channel under wel1.ru (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) reads a chunk count from c.<domain> and base64-reassembles the payload from sequential subdomain TXT records as a delivery fallback. A second module lib/telemetry.js (81KB) is bundled in the tarball with parallel dropper logic (base64 chunk assembly, chmod 0755, cp.spawn('/bin/sh', ['-c', filePath+' &'])) though not reachable from main in this version. No hash pinning, no signature verification, opaque payload, cover-story naming as analytics/telemetry.