{"id":"MAL-2026-12602","summary":"Malicious code in checkout-use-notifications (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (1a9b7cb00a4aac61795c81a085319cb8b0ac0aff1350a0dafddb4ef31d25a15f)\nOn require of the package, index.js unconditionally loads _shim.js, which fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev) with a DNS TXT-record fallback channel via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. Hostnames are assembled at runtime by joining split string fragments to evade static detection. The fetched payload is written to /tmp or %TEMP% under disguised names (.cache_\u003crand\u003e, dotnet_diag_\u003crand\u003e.exe), chmod 0755 on Unix, and spawned detached via /bin/sh -c or cmd with stdio ignored. The DNS fallback base64-decodes numbered TXT chunks to reconstruct the payload when HTTPS fetches fail. An anti-re-run stamp gates repeated execution. The delivery infrastructure, string-split hostname obfuscation, disguised on-disk filenames, and DNS covert channel are canonical malicious dropper fingerprints.\n","modified":"2026-08-05T14:35:44.459138057Z","published":"2026-08-05T14:07:07Z","database_specific":{"malicious-packages-origins":[{"versions":["35.6.1"],"id":"IN-MAL-2026-015171","import_time":"2026-08-05T14:20:09.32905207Z","modified_time":"2026-08-05T14:07:07Z","sha256":"1a9b7cb00a4aac61795c81a085319cb8b0ac0aff1350a0dafddb4ef31d25a15f","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/checkout-use-notifications/v/35.6.1"}],"affected":[{"package":{"name":"checkout-use-notifications","ecosystem":"npm","purl":"pkg:npm/checkout-use-notifications"},"versions":["35.6.1"],"database_specific":{"indicators":{"evidence_files":[{"path":"_shim.js","sha256":"d331a36097697d8b731039cdfbd48b6f90fb9c60c44847372d889787db75cd5b","tlsh":"97a1a85a1666701887b09be5c7274419f95bf2633780c294fb9ca5981fb35248372dfc"}],"package_integrity":[{"hashes":{"sha1":"0d903232516a6e0012136cb64c5936515ae923d1","sha512_sri":"sha512-Xv/xqugpoRsnJML/Py+C2KgzYyBXdS7fG4nsOFoPBwNq4ub8PwZ1F/YwtWzJ6ERBivPYn8qmoyQoMg5YsZ0TqA=="},"filename":"checkout-use-notifications-35.6.1.tgz"}]},"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-use-notifications/MAL-2026-12602.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}