{"answers":{"affected":"1 open source package ship an affected version, including express-middle.","exploited":"There is no known exploitation of MAL-2026-12376 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-2026-12376 is a malicious package in express-middle, published on 5 Aug 2026."},"fix_prompt":"MAL-2026-12376 is a malicious package: express-middle (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-2026-12376/ (Markdown: https://insights.sbomify.com/MAL-2026-12376/index.md)","id":"MAL-2026-12376","markdown":"https://insights.sbomify.com/MAL-2026-12376/index.md","name":"MAL-2026-12376","record":{"aliases":[],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"package.json declares postinstall: `node index.js`, which fires automatically on `npm install`. index.js is a heavily obfuscated bundle (obfuscator.io-style RC4-decoded 344-entry string array with control-flow flattening) whose runtime behavior assembles a destination host at runtime by concatenating four numeric fragments with '.' (an IPv4 built to hide the C2 from static review), performs an HTTPS request to that host, splits the response on ':' into IV and ciphertext, derives a key via pbkdf2, AES-decrypts the response with createDecipheriv, writes the plaintext payload to disk via fs.writeFileSync, and executes it through child_process.exec with `windowsHide:true` to suppress a console window. The package name resembles `express` middleware but ships no middleware functionality; the sole effect of installing it is remote code execution on the installer's machine under attacker control.","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 express-middle (npm)","id":"MAL-2026-12376","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":"express-middle","purl":"pkg:npm/express-middle","source":"MAL-2026-12376"}],"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-2026-12376/"}