{"answers":{"affected":"1 open source package ship an affected version, including claims-get-error-string.","exploited":"There is no known exploitation of MAL-2026-12620 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-2026-12620 is a malicious package in claims-get-error-string, published on 5 Aug 2026."},"fix_prompt":"MAL-2026-12620 is a malicious package: claims-get-error-string (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-2026-12620/ (Markdown: https://insights.sbomify.com/MAL-2026-12620/index.md)","id":"MAL-2026-12620","markdown":"https://insights.sbomify.com/MAL-2026-12620/index.md","name":"MAL-2026-12620","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(), index.js loads _ext.js which downloads a platform-specific binary from a set of hardcoded Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev) assembled by string-splitting to evade static matching. The downloaded bytes are written to /var/tmp or %TEMP% under innocuous names (.cache_\u003crnd\u003e on POSIX, dotnet_diag_\u003crnd\u003e.exe on Windows), chmod 0755 is applied, and the binary is spawned detached via /bin/sh -c '\u003cpath\u003e \u0026' or cmd. A DNS-TXT covert channel under wel1.ru (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) reads a chunk count from c.\u003cdomain\u003e and base64-reassembles the payload from sequential subdomain TXT records as a delivery fallback. A second module lib/telemetry.js (81KB) is bundled in the tarball with parallel dropper logic (base64 chunk assembly, chmod 0755, cp.spawn('/bin/sh', ['-c', filePath+' \u0026'])) though not reachable from main in this version. No hash pinning, no signature verification, opaque payload, cover-story naming as analytics/telemetry.","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 claims-get-error-string (npm)","id":"MAL-2026-12620","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":"claims-get-error-string","purl":"pkg:npm/claims-get-error-string","source":"MAL-2026-12620"}],"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-2026-12620/"}