{"id":"MAL-2026-13260","summary":"Malicious code in devplatform-spa-plugin-s3 (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (8ca84ec076b60ced1412d45476eb90fb5c797b8dd53a5151d474dc979a085565)\ndevplatform-spa-plugin-s3@35.5.9 is a binary dropper. index.js unconditionally requires _shim.js, whose top-level init() fetches a platform-specific binary over HTTPS from destinations reassembled at runtime by joining split string fragments (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), writes it to /tmp or a Windows temp directory under disguised names such as dotnet_diag_\u003crnd\u003e.exe and.cache_\u003crnd\u003e, chmods it to 0755, and spawns it detached via cp.spawn('/bin/sh',['-c', fp+' &'],{detached:true}) or cp.spawn('cmd.exe',['/c','start','/b',fp]). A covert-channel fallback reconstructs the payload from base64 chunks served in DNS TXT records under *.dl.wel1.ru (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru). Execution is gated by a /tmp/.analytics_state cache stamp using telemetry cover-story naming (analytics_state, dotnet_diag_) to camouflage the drop. A second equivalent dropper module is bundled at lib/telemetry.js and uses split-string require (require('child_'+'process')) and computed method names (fs['chmod'+'Sync']) to hide the import and API surface from static scanners. The destination hosts are unrelated to any legitimate S3/SPA plugin publisher, the payload is unpinned and unverified, and the execution path fires on any require() of the package.\n","modified":"2026-08-05T16:50:21.804201620Z","published":"2026-08-05T15:31:12Z","database_specific":{"malicious-packages-origins":[{"modified_time":"2026-08-05T15:31:12Z","sha256":"8ca84ec076b60ced1412d45476eb90fb5c797b8dd53a5151d474dc979a085565","source":"amazon-inspector","versions":["35.5.9"],"id":"IN-MAL-2026-015730","import_time":"2026-08-05T16:13:37.208458566Z"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/devplatform-spa-plugin-s3/v/35.5.9"}],"affected":[{"package":{"name":"devplatform-spa-plugin-s3","ecosystem":"npm","purl":"pkg:npm/devplatform-spa-plugin-s3"},"versions":["35.5.9"],"database_specific":{"cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"evidence_files":[{"sha256":"179095c0301e998066a3b83ac953839ce717151df42b1b2d4c24f555aed15fa1","tlsh":"cca1a49616a670184bb0a7e4c61b8815f65bf66337c182c4f79ca5984fb351483b2efc","path":"_shim.js"},{"path":"lib/telemetry.js","sha256":"699e78f63c76f6bd83b2ca70cd570747b0993a32c4354e15b5f7f3303d136b41","tlsh":"c9835056566a142186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"}],"package_integrity":[{"filename":"devplatform-spa-plugin-s3-35.5.9.tgz","hashes":{"sha1":"244f36a6910197d1aa9d8bcf2a4bdc0fcb7fcd8c","sha512_sri":"sha512-J7qLuPRoOIxmq9dRwxCT1q2F8ItKvymBjo+aAOr+QF6Eagfs+4jx6+No08RYPxmZq7zwgWnmfZHKyyCFb7JM6Q=="}}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/devplatform-spa-plugin-s3/MAL-2026-13260.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}