{"id":"MAL-2026-13070","summary":"Malicious code in boxy-mm-server-loader (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (26c25489d15bfaaf8e337af2f2fa446e86fdc8cc5fae3199be2451bdb35196ef)\nOn `require('boxy-mm-server-loader')`, index.js loads _polyfill.js, which fetches a platform-specific binary from one of three string-split-obfuscated Cloudflare Workers hosts (oob-worker.cf102-baf.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev), writes it to /var/tmp/.cache_\u003chex\u003e on Unix or %TEMP%/dotnet_diag_\u003chex\u003e.exe on Windows, chmods 0755, and spawns it detached via `/bin/sh -c` or `cmd.exe /c start /b`. A DNS TXT-record covert channel over c.\u003cdomain\u003e / 0.\u003cdomain\u003e / 1.\u003cdomain\u003e against sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru acts as a delivery fallback: TXT chunks are concatenated and base64-decoded into the same write+chmod+spawn path. Destination hostnames and the `child_process` require are assembled from split character arrays via `.join(\"\")`; dropped artifacts use decoy names mimicking system telemetry (.cache_\u003chex\u003e, dotnet_diag_\u003chex\u003e.exe,.analytics_state). No hash or signature verification is performed on the fetched bytes.\n","modified":"2026-08-05T15:52:09.128226462Z","published":"2026-08-05T14:27:36Z","database_specific":{"malicious-packages-origins":[{"modified_time":"2026-08-05T14:27:36Z","sha256":"26c25489d15bfaaf8e337af2f2fa446e86fdc8cc5fae3199be2451bdb35196ef","source":"amazon-inspector","versions":["35.5.8"],"id":"IN-MAL-2026-015309","import_time":"2026-08-05T15:19:44.042426019Z"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/boxy-mm-server-loader/v/35.5.8"}],"affected":[{"package":{"name":"boxy-mm-server-loader","ecosystem":"npm","purl":"pkg:npm/boxy-mm-server-loader"},"versions":["35.5.8"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"package_integrity":[{"hashes":{"sha512_sri":"sha512-95i+EO9qqAcVw7yIuS+hw++Vfo43eh7xiOZmKXD5iKQpxKtFhboZ9HDsUtk3fnOvNxjmQ0JUuVvp2lxPxDVL1w==","sha1":"500a103c2166d0ad860a66e9f83983b459e3a862"},"filename":"boxy-mm-server-loader-35.5.8.tgz"}],"evidence_files":[{"path":"_polyfill.js","sha256":"c29296b8c7c067a6e6dfda30b6e147e011d7192869bf97a4712287c556de846f","tlsh":"0aa1b79a06a6701987b0dbe087174816f65ff6633380c284fb9c69985f7712483b2efc"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/boxy-mm-server-loader/MAL-2026-13070.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}