MAL-2026-12900 Malicious code in bnpl-blocks-atom-container (npm)

On require() of bnpl-blocks-atom-container, index.js loads adapter.js which selects a platform-specific target path, downloads an opaque binary from one of four Cloudflare Workers hosts whose names are reconstructed at runtime from split string fragments (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), writes it to /var/tmp or %TEMP% under cover-story filenames ('dotnet_diag<hex>.exe' on Windows, '.cache_<hex>' on Unix), chmods 0755, and spawns it detached via '/bin/sh -c <fp> &' or 'cmd.exe /c start /b <fp>'. A stamp file named '.analytics_state' under /tmp gates re-execution. When HTTPS delivery fails, the loader falls back to a DNS-over-TXT channel against *.dl.wel1.ru (sdk./ext./pkg./net.dl.wel1.ru): it reads a chunk count from a 'c.<domain>' TXT record, retrieves N indexed base64 TXT records, concatenates and base64-decodes them into the payload bytes, and executes the result. Hostname obfuscation, disguised staging filenames, and a redundant covert DNS delivery channel are consistent with evasion of both static scanners and HTTP egress controls, not with any legitimate SDK loader.