{"answers":{"affected":"1 open source package ship an affected version, including boxy-esm-shims.","exploited":"There is no known exploitation of MAL-2026-13042 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-2026-13042 is a malicious package in boxy-esm-shims, published on 5 Aug 2026."},"fix_prompt":"MAL-2026-13042 is a malicious package: boxy-esm-shims (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-2026-13042/ (Markdown: https://insights.sbomify.com/MAL-2026-13042/index.md)","id":"MAL-2026-13042","markdown":"https://insights.sbomify.com/MAL-2026-13042/index.md","name":"MAL-2026-13042","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() of the package, index.js loads _vendor.js which fetches an opaque binary from string-obfuscated Cloudflare Workers hosts (oob-worker.cf103-07.0.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev) with a DNS-TXT base64 fallback under *.wel1.ru (sdk.dl.wel1.ru). The downloaded bytes are written to /var/tmp or %TEMP% under a disguised name (.cache_\u003chex\u003e on Unix, dotnet_diag_\u003chex\u003e.exe on Windows), chmodded 0755, and spawned detached via /bin/sh -c or cmd.exe with unref(). Destination hostnames and the child_process require are assembled from split string fragments via Array.join to evade static matching, and the fetch is framed as telemetry with cover-story opt-out env vars (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK). A TTL stamp file suppresses repeat execution.","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 boxy-esm-shims (npm)","id":"MAL-2026-13042","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":"boxy-esm-shims","purl":"pkg:npm/boxy-esm-shims","source":"MAL-2026-13042"}],"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-2026-13042/"}