MAL-2026-11958 Malicious code in @umacloud/cli-linux-x64 (npm)

npm/@umacloud/cli-linux-x64 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.

The package advertises itself as a prebuilt Linux x86_64 binary shipping bin/umadev, but its preinstall script (node setup.mjs) performs an alternate-runtime dropper sequence on every npm install: it checks for a local bun binary, and when absent downloads the Bun runtime zip from the oven-sh/bun GitHub releases, extracts it to a tmp directory, chmods it executable (mode 493 / 0755), then invokes execFileSync on the downloaded Bun binary passing math_init.js as the script to run. math_init.js is a 727 KB Bun-compiled bundle (// @bun @bun-cjs) using string-array rotation (WV8StW shift function), a large numeric/string constant array, hex identifiers, and a custom base-N string decoder (hc1jfK9); its runtime behavior is not verifiable from source review. Both setup.mjs and math_init.js ship at the tarball root but are absent from the declared files manifest, which lists only bin/. The install-time payload filename (math_init.js) is unrelated to the package's stated purpose of delivering a prebuilt binary, and the shipped bin/umadev.provenance.json declares version 1.0.73 while the package itself is version 1.0.74, so the provenance does not cover the shipped binary. A prebuilt-binary package has no functional need to fetch a second language runtime and execute an obfuscated JS bundle at install time.

Any 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.