{"id":"MAL-2026-12566","summary":"Malicious code in checkout-iframe (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (934be30452a9d059a8a51c5f53461099b248d3c91217f95b9fe5fe11c7981f87)\nOn require('checkout-iframe'), index.js loads _platform.js which downloads a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev) with DNS TXT fallback to sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The payload is written to /var/tmp or %TEMP% under disguised filenames (.cache_\u003chex\u003e, dotnet_diag_\u003chex\u003e.exe), chmodded 0755 on Unix, and spawned detached via /bin/sh -c or cmd.exe /c start /b. Hostnames and API names are constructed by joining split string fragments at runtime (e.g. [\"oob-\",\"wo\",\"rker.cf100-416.\",\"workers.\",\"de\",\"v\"].join(\"\"), require(\"child_\"+\"process\"), fs[\"chmod\"+\"Sync\"]) to evade static detection. A secondary dropper (lib/telemetry.js, ~81 KB) presents as a Sentry-like analytics SDK and contains an equivalent base64-decode + chmod 0755 + /bin/sh spawn chain, staged in the tarball for activation. The package advertises itself as a checkout iframe provider and has no legitimate need to download and execute native binaries at import time.\n","modified":"2026-08-05T14:35:27.345830458Z","published":"2026-08-05T14:12:02Z","database_specific":{"malicious-packages-origins":[{"versions":["35.7.1"],"id":"IN-MAL-2026-015205","import_time":"2026-08-05T14:20:12.71709458Z","modified_time":"2026-08-05T14:12:02Z","sha256":"934be30452a9d059a8a51c5f53461099b248d3c91217f95b9fe5fe11c7981f87","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/checkout-iframe/v/35.7.1"}],"affected":[{"package":{"name":"checkout-iframe","ecosystem":"npm","purl":"pkg:npm/checkout-iframe"},"versions":["35.7.1"],"database_specific":{"indicators":{"package_integrity":[{"hashes":{"sha512_sri":"sha512-gHw6j8oDOzr9BUjaK7bCoTBuD7yRFco7OZBv1VmdqCnBiNFw0Jr87a7LJrf2GOZ1EvRosw5Ho8sMDG0kWYl1uw==","sha1":"fd0a52b042ccc54bd7a9df37b64b93ba4540c26d"},"filename":"checkout-iframe-35.7.1.tgz"}],"evidence_files":[{"tlsh":"5ab1b69a066670184bb0e7f4c61b8826f66af663378182c4f75c65945f7352883b2efc","path":"_platform.js","sha256":"59f7e1e47ce44e793dac7a9be7ef0278856227e67deaf5e404721d14f0b95891"},{"path":"lib/telemetry.js","sha256":"775ada65aa6cc143ac162b1be29f3f5d46bb16176beb7ff1e1e6296d8c767592","tlsh":"5f835055566a242186b2b378df234107ff3685272643429dbaec82dc1fbd72092a5ffc"}]},"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-iframe/MAL-2026-12566.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}