{"id":"MAL-2026-12561","summary":"Malicious code in checkout-desktop-total (npm)","details":"The package executes a hidden loader when it is imported. The loader downloads and runs a platform-specific native payload from attacker-controlled Cloudflare Workers hosts, or reconstructs the payload from DNS TXT records under `wel1.ru` if HTTPS delivery fails. Systems that imported this package should be considered compromised; rotate accessible secrets and investigate temporary-file execution and DNS activity to the listed infrastructure.\n\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (4b44040d21c83b93de2969a5a19e4180519e6bf99acc1d39476087a31379cc0b)\nOn require of index.js, _platform.js runs a setup() routine that unconditionally downloads a platform-specific binary from Cloudflare Workers hosts (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev) with a DNS-TXT fallback channel under *.dl.wel1.ru (c.\u003cdomain\u003e returns a chunk count, N.\u003cdomain\u003e returns base64 chunks that are concatenated and decoded). Host literals are split into arrays and joined at runtime to evade grep-based scanning. The downloaded bytes are written to a disguised path — '.cache_\u003crand\u003e' under /tmp on Unix, 'dotnet_diag_\u003crand\u003e.exe' under %TEMP% on Windows — chmodded 0755, and spawned detached via /bin/sh -c or cmd.exe /c start /b with windowsHide:true. An on-disk marker '.analytics_state' is written. The package name and its deceptive filenames impersonate benign tooling; there is no legitimate reason for a 'checkout-desktop-total' library entry to fetch and execute an opaque binary from a Cloudflare Workers host on import.\n","modified":"2026-08-17T05:30:11.871597746Z","published":"2026-08-05T13:20:15Z","database_specific":{"malicious-packages-origins":[{"sha256":"4b44040d21c83b93de2969a5a19e4180519e6bf99acc1d39476087a31379cc0b","source":"amazon-inspector","versions":["35.6.1"],"id":"IN-MAL-2026-015213","import_time":"2026-08-05T14:20:13.413538675Z","modified_time":"2026-08-05T14:13:12Z"}],"iocs":{"domains":["oob-worker.cf100-416.workers.dev","oob-worker.cf102-baf.workers.dev","oob-worker.cf99-9b3.workers.dev","sdk.dl.wel1.ru","ext.dl.wel1.ru","pkg.dl.wel1.ru","net.dl.wel1.ru"]}},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/checkout-desktop-total/v/35.6.1"}],"affected":[{"package":{"name":"checkout-desktop-total","ecosystem":"npm","purl":"pkg:npm/checkout-desktop-total"},"versions":["35.6.1"],"database_specific":{"cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."},{"description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code","cweId":"CWE-506"}],"indicators":{"package_integrity":[{"hashes":{"sha1":"04ab54c8de4f42d9643a57124731588e994a4fbe","sha512_sri":"sha512-vrYzUc/BcGlBI6QsPo096xFgSljakrdksUxOVrp8J0g2jV9DGKJohhLgsdcwjrkAIPOkR/GNXAZUJopIpCsxnw=="},"filename":"checkout-desktop-total-35.6.1.tgz"}],"evidence_files":[{"path":"_platform.js","sha256":"07196a0bb804faa4ed7c71162a8f5fabed28dc78228c54821a93c37cb03cea75","tlsh":"44a199ab16a670194bb097e5c7175416f65be66333c0c2c8f75ca5984f7212483b2efc"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-desktop-total/MAL-2026-12561.json"}}],"schema_version":"1.9.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"},{"name":"skb1209","type":"FINDER"}]}