checkout-post-installment-client-agreement-accept-am

{"modified":"2026-08-05T14:08:52Z","published":"2026-08-05T14:08:52Z","schema_version":"1.7.4","id":"MAL-2026-12586","summary":"Malicious code in checkout-post-installment-client-agreement-accept-am (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (3562600b17ec6918b0ebfda948a4579addb4bf1d55a39c696bf6b10fcc15020f)\nOn require(), index.js loads _support.js which assembles Cloudflare Workers hostnames (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev) via array-join concealment and fetches a platform-specific binary over HTTPS, with a DNS-TXT base64-chunk fallback channel served from sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru and net.dl.wel1.ru. The retrieved bytes are written to a temp path with a disguised name (.cache_<rnd> on Unix, dotnet_diag_<rnd>.exe on Windows), chmod 0755'd, and detached-spawned via /bin/sh -c or cmd /c start, so the payload runs at import time with the installer's privileges. A second dropper implementation with the same fetch/write/chmod 755/spawn primitives is bundled in lib/telemetry.js under an 'Analytics SDK' cover story, using concatenated API names (chmod+Sync, child_+process) and base64 buffer decoding. Package name and 'telemetry/analytics' framing are cover-story labels; the actual behavior is remote code delivery and execution on the installer's host from author-controlled infrastructure.\n","affected":[{"package":{"ecosystem":"npm","name":"checkout-post-installment-client-agreement-accept-am"},"versions":["35.2.3"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"path":"_support.js","sha256":"c38f749b835577d11fb9bb9fe9a1c37a99cfa8a027476434c85019db6dbb71c9","tlsh":"92a1875a16a670198b70ebe4c7175816f65af6633380c2d4f79c59941fb312483b2efc"},{"path":"lib/telemetry.js","sha256":"ec1c30eb1c6eb66319649d5dae8df8a05ced88a0c0559a904f68ec79da28f6b2","tlsh":"27835055566a602186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"}],"package_integrity":[{"filename":"checkout-post-installment-client-agreement-accept-am-35.2.3.tgz","hashes":{"sha1":"d5aae9b1e9e09f6ef65051351f439d2abbc47a21","sha512_sri":"sha512-pxQeEY3W+F3PL8cT4oWjvKyflyBxBAanxeSaDg9j9L9sm43ll0DLTyE2QAB3n9HzN9HLujqZ6rmTf0KN8G1/Lg=="}}]}}}],"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/checkout-post-installment-client-agreement-accept-am/v/35.2.3"}],"credits":[{"name":"Amazon Inspector","type":"FINDER","contact":["inspector-research@amazon.com"]}],"database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-015184","import_time":"2026-08-05T14:20:10.59964593Z","modified_time":"2026-08-05T14:08:52Z","sha256":"3562600b17ec6918b0ebfda948a4579addb4bf1d55a39c696bf6b10fcc15020f","source":"amazon-inspector","versions":["35.2.3"]}]}}