http-uploader-devnpm

package.json declares "preinstall": "bun run index.js", which on npm install invokes Bun to run index.js. index.js detects the host OS and shells out to launch an unrelated local application — open -a Calculator on macOS, calc.exe on Windows, and xcalc/gnome-calculator/kcalc on Linux — via execSync. This is the canonical proof-of-concept install-time RCE payload and bears no relation to the package's stated 'http uploader' purpose. Two independently suspicious structural traits compound the lifecycle behavior: (1) the preinstall hook routes execution through Bun, an alternate runtime fetched outside the normal Node resolution path, matching the alternate-runtime-dropper pattern; (2) package metadata is placeholder/throwaway (author 'sleep', homepage https://git.hfaf.com/urlaa, generic name 'http-uploader-dev'). The PoC nature of the current payload (launching a calculator) does not lower the severity: any installer running npm install http-uploader-dev executes attacker-chosen commands at install time, and a future republish can swap in arbitrary code with no change to the trigger surface.

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.