MAL-2026-12530

Dashboard / Malicious Package / MAL-2026-12530

MAL-2026-12530

Summary: Malicious code in cardsmobile-command-utils (npm)

Details: Source: amazon-inspector (36cfe57bdba8edd36f9303058545ce1097dd496f1c32304f1d8d912ccf321480) On require(), index.js loads _bridge.js which selects a platform-specific URL, downloads a binary over HTTPS from author-controlled Cloudflare Workers subdomains, writes it to a hidden temp path with a decoy name (`.cache_<hex>` on Unix, `dotnet_diag_<hex>.exe` on Windows), chmods it to 0755, and spawns it detached via `/bin/sh` or `cmd.exe`. The destination hostnames are constructed via `[...].join('')` string-fragment obfuscation (e.g. `["oob-","worker.cf","102-baf.work","ers.d","ev"].join("")` resolving to `oob-worker.cf102-baf.workers.dev`, plus `oob-worker.cf101-adf.workers.dev` and `oob-worker.cf100-416.workers.dev`) to defeat static searches for the C2 infrastructure. If HTTPS fetches fail, `_bridge.js` falls back to a DNS TXT covert channel: it queries a chunk count at `c.<domain>` and reassembles a base64-encoded payload from `<i>.<domain>` TXT records under attacker-controlled zones `sdk.dl.wel1.ru`, `ext.dl.wel1.ru`, `pkg.dl.wel1.ru`, and `net.dl.wel1.ru`. No signature or hash verification is performed on the fetched bytes, decoy filenames masquerade as.NET diagnostics/cache artifacts, staging uses hidden dot-files, execution is detached, and the loader honors DO_NOT_TRACK to suppress activity on researcher machines. Cover-story comments (`// Clean up temporary files after extraction`, `// Binary-safe buffer concatenation`) are unrelated to the surrounding code.

References: https://www.npmjs.com/package/cardsmobile-command-utils/v/35.9.2