{"answers":{"affected":"1 open source package ship an affected version, including checkout-iframe.","exploited":"There is no known exploitation of MAL-2026-12566 in the wild and no public exploit code.","fix":"Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.","what":"MAL-2026-12566 is a malicious package in checkout-iframe, published on 5 Aug 2026."},"fix_prompt":"MAL-2026-12566 is a malicious package: checkout-iframe (npm). Every version was published to cause harm.\n\nTask:\n1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.\n2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.\n3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.\n4. If the package is not used anywhere, say so and change nothing.\n\nReference: https://insights.sbomify.com/MAL-2026-12566/ (Markdown: https://insights.sbomify.com/MAL-2026-12566/index.md)","id":"MAL-2026-12566","markdown":"https://insights.sbomify.com/MAL-2026-12566/index.md","name":"MAL-2026-12566","record":{"aliases":[],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"On 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.","ecosystems":["npm"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":false,"headline":"Malicious code in checkout-iframe (npm)","id":"MAL-2026-12566","indexable":true,"kev":null,"kind":"malicious","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":1,"n_references":null,"packages":[{"ecosystem":"npm","fixed":[],"introduced":[],"last_affected":[],"package":"checkout-iframe","purl":"pkg:npm/checkout-iframe","source":"MAL-2026-12566"}],"products":null,"published":"2026-08-05","related":[],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"OpenSSF Malicious Packages","prefix":"MAL"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":null,"url":"https://insights.sbomify.com/MAL-2026-12566/"}