{"id":"MAL-2026-13201","summary":"Malicious code in dp-web-header (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (ec4c10894526621b93c3dba8f579e76be53db3989ab0ddb32c72bff180266786)\nThe package advertises itself as a web header library but its index.js unconditionally requires _ext.js on load. _ext.js downloads a platform-specific binary from hardcoded Cloudflare Workers hosts (oob-worker.cf100-416.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 it 0755, and spawns it detached via spawn('/bin/sh',...) or spawn('cmd',...). If the HTTPS fetch to the Workers hosts fails, the module falls back to a DNS-TXT covert channel resolving c.\u003cdomain\u003e, 0.\u003cdomain\u003e, 1.\u003cdomain\u003e,... under sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru, concatenating and base64-decoding the labels into the same executable bytes. The C2 hostnames are assembled via array-join to evade string search, the dropped filenames impersonate legitimate diagnostics tooling (dotnet_diag_*.exe,.cache_*), a marker file.analytics_state is written, and a comment claiming a SHA-256 integrity check is present with no actual hash verification in code. Installing or importing the package executes attacker-controlled native code on the installer's host.\n","modified":"2026-08-05T15:53:10.747364759Z","published":"2026-08-05T15:07:07Z","database_specific":{"malicious-packages-origins":[{"versions":["35.3.8"],"id":"IN-MAL-2026-015573","import_time":"2026-08-05T15:19:58.557076068Z","modified_time":"2026-08-05T15:07:07Z","sha256":"ec4c10894526621b93c3dba8f579e76be53db3989ab0ddb32c72bff180266786","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/dp-web-header/v/35.3.8"}],"affected":[{"package":{"name":"dp-web-header","ecosystem":"npm","purl":"pkg:npm/dp-web-header"},"versions":["35.3.8"],"database_specific":{"cwes":[{"description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code","cweId":"CWE-506"}],"indicators":{"evidence_files":[{"tlsh":"4ca1959a16a670188bb0dbe4c7175416f65be6632780c5c4fb9ca4885fb322483b1efc","path":"_ext.js","sha256":"026ace94d3bfa2f76e3edb09f6eff5a206c345788b31a243111a4754665336e0"}],"package_integrity":[{"filename":"dp-web-header-35.3.8.tgz","hashes":{"sha1":"9de64cf8a9f70a1c911c10b14f1e45513734a005","sha512_sri":"sha512-lISe4YXgA8xrS9+0xFzR+0BUyUXC3IUBI7miXXV3eXlqZkPUlrEULMtzDDWFkbW0Yl3szS9tRGEZFzNoZjLd9g=="}}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/dp-web-header/MAL-2026-13201.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}