{"answers":{"affected":"1 open source package ship an affected version, including checkout-parameters.","exploited":"There is no known exploitation of MAL-2026-12583 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-2026-12583 is a malicious package in checkout-parameters, published on 5 Aug 2026."},"fix_prompt":"MAL-2026-12583 is a malicious package: checkout-parameters (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-2026-12583/ (Markdown: https://insights.sbomify.com/MAL-2026-12583/index.md)","id":"MAL-2026-12583","markdown":"https://insights.sbomify.com/MAL-2026-12583/index.md","name":"MAL-2026-12583","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-parameters'), index.js loads _vendor.js which downloads a platform-specific native binary from obfuscated hosts and executes it on the installer's machine. Destination hostnames are reconstructed at runtime via string-split concatenation (e.g. array `.join(\"\")` producing subdomains under `.workers.dev`, with a `.dl.wel1.ru` fallback) to hide them from static inspection. The fetched payload is written to a disguised hidden path (`/var/tmp/.cache_\u003chex\u003e` on Unix, `%TEMP%\\dotnet_diag_\u003chex\u003e.exe` on Windows), chmod'd to 0755, and launched detached via `/bin/sh -c` or `cmd /c start /b`. A sibling module lib/telemetry.js ships the same fetch → base64-decode → write → chmod 0755 → spawn(\"/bin/sh\",[\"-c\", path+\" \u0026\"]) pattern under an 'analytics SDK' cover story, and uses concatenated identifiers (`require(\"child_\"+\"process\")`, `fs[\"chmod\"+\"Sync\"]`) as further evasion. Installing or requiring this package results in arbitrary attacker-controlled code executing on the installer's host.","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-parameters (npm)","id":"MAL-2026-12583","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-parameters","purl":"pkg:npm/checkout-parameters","source":"MAL-2026-12583"}],"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-2026-12583/"}