OpenSSF/OSV advisory MAL-2026-13521 confirms this npm version as malicious. scripts/postinstall.js runs at npm install time. On Windows it downloads a ZIP archive from https://files.catbox.moe/rp8idk.zip (anonymous file-hosting service, mutable content), uses PowerShell Expand-Archive to unpack it to a randomized temp directory, then spawns a bundled pythonw.exe against exec_.py with detached:true, stdio:'ignore', windowsHide:true, and child.unref(), so the fetched payload runs hidden and...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in @rbxst/services (npm)
Details
scripts/postinstall.js runs at npm install time. On Windows it downloads a ZIP archive from https://files.catbox.moe/rp8idk.zip (anonymous file-hosting service, mutable content), uses PowerShell Expand-Archive to unpack it to a randomized temp directory, then spawns a bundled pythonw.exe against exec_.py with detached:true, stdio:'ignore', windowsHide:true, and child.unref(), so the fetched payload runs hidden and outlives the npm process. The script exits silently on non-Windows platforms. The package advertises roblox-ts service type utilities and has no legitimate need to fetch and execute a Python interpreter from an anonymous file host. This matches the alternate-runtime dropper pattern from known-bad infrastructure: an opaque remote payload executes on the installer's machine with the installer's privileges.
Decision reason
OpenSSF Malicious Packages via OSV confirms @rbxst/services@1.0.756 as malicious (MAL-2026-13521): Malicious code in @rbxst/services (npm)