{"answers":{"affected":"1 open source package ship an affected version, including @arv-bedrock/auth-sso-backend.","exploited":"There is no known exploitation of MAL-2026-11556 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-2026-11556 is a malicious package in @arv-bedrock/auth-sso-backend, published on 4 Aug 2026."},"fix_prompt":"MAL-2026-11556 is a malicious package: @arv-bedrock/auth-sso-backend (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-2026-11556/ (Markdown: https://insights.sbomify.com/MAL-2026-11556/index.md)","id":"MAL-2026-11556","markdown":"https://insights.sbomify.com/MAL-2026-11556/index.md","name":"MAL-2026-11556","record":{"aliases":["GHSA-mh3h-7fpv-657f"],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"npm/@arv-bedrock/auth-sso-backend is affected by the large-scale, self-propagating npm supply-chain worm of 2026-08-04 (the \"Shai-Hulud: Here We Go Again\" wave) — the same campaign that began with the compromise of the keyv and cacheable maintainer account. The listed version(s) were trojanized and republished by the worm after it reached an npm publish token belonging to a maintainer in this namespace; the payload enumerates every package a stolen token controls and republishes each with the same hook, so many packages under this scope were poisoned in the same short window. Every poisoned release adds a preinstall hook (`\"preinstall\": \"node setup.mjs\"`) that runs on a bare `npm install`, before any project code. setup.mjs downloads a standalone Bun runtime and runs a byte-identical, heavily obfuscated ~728 KB second-stage credential stealer (shipped as Math_Symbol.js / math_init.js). It harvests GitHub, npm, AWS, GCP, Azure, HashiCorp Vault and Kubernetes credentials plus generic secrets and private keys (TruffleHog-style sweep), reads CI/CD secrets and identifies build runners, then republishes further packages the stolen token can reach. Rather than a fixed command-and-control host, it exfiltrates stolen findings to attacker-created GitHub repositories (descriptions reading \"Shai-Hulud: Here We Go Again\") and over DNS. Treat any environment that installed an affected version (with install scripts enabled) as compromised: rotate and revoke all reachable credentials (npm and GitHub tokens, cloud keys, Vault/Kubernetes secrets, and CI org/repo secrets). Part of the August 2026 npm worm that poisoned 400+ packages across many organizations.\n\nThe package declares a preinstall hook `node setup.mjs` that downloads the Bun runtime (v1.3.13) from GitHub, extracts it to a temporary directory, chmods it executable, and invokes it via `execFileSync(bunPath, [math_init.js], {cwd:D})` to run a package-local file `math_init.js`. `math_init.js` is a 727KB single-line heavily obfuscated bundle (header `// @bun @bun-cjs`, hex-name identifiers, a multi-thousand-entry mixed literal array driving a rotating string-array decoder function `WV8StW`). The obfuscated payload is not referenced from the declared library entrypoint (`dist/cjs/index.js`) and is not listed in `package.json.files` (which allows only `dist/**/*`); it exists in the tarball solely to be executed by the preinstall dropper. Package metadata is placeholder (`author: \"\"`, `description: \"\"`) and the README contains only pipeline-trigger notes, with no relation to the advertised SSO-backend purpose. Executing under a freshly downloaded alternate runtime bypasses Node-based install-time monitoring, and the opaque payload's behavior cannot be inspected by the installer.\n\nAny computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.","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 @arv-bedrock/auth-sso-backend (npm)","id":"MAL-2026-11556","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":"@arv-bedrock/auth-sso-backend","purl":"pkg:npm/%40arv-bedrock/auth-sso-backend","source":"MAL-2026-11556"}],"products":null,"published":"2026-08-04","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-2026-11556/"}