MalwarePublished 7 Aug 2026

@rbxst/services (npm) · Malicious Code

Affects @rbxst/servicesSource GCVE Database

Malicious package : remove @rbxst/services and rotate any secrets on hosts that installed it.

Data as of 7 Aug 2026, 15:37 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-13521

What to do

Remove @rbxst/services from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
npm@rbxst/services	Affected =1.0.756	Fixed in–

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Description

The npm package @rbxst/services version 1.0.756 contains malicious code that executes during installation on Windows systems. The postinstall.js script downloads a ZIP archive from an anonymous file-hosting service, extracts it using PowerShell, and runs a hidden Python payload with the installer's privileges. This behavior is suspicious and matches known malicious patterns of remote payload execution. The package falsely advertises Roblox-TS service utilities but has no legitimate reason to fetch and run external Python code. This threat does not have a CVSS score but is assessed as high severity due to the execution of opaque remote code with user privileges.

Impact

The malicious postinstall script enables execution of arbitrary code downloaded from an untrusted, anonymous source with the privileges of the user running npm install on Windows. This can lead to system compromise, persistence of malicious code, and potential further exploitation. The payload runs hidden and detached, making detection difficult during installation. There is no indication of exploitation in the wild yet, but the risk of compromise is high if the package is installed.

Defensive guidance

Users should avoid installing @rbxst/services version 1.0.756. Remove any installations of this package and audit systems for signs of compromise if it was installed. Use trusted package sources and verify package integrity before installation. Monitor for updates from the npm registry or security advisories for any remediation or removal actions.

Summary

The @rbxst/services npm package version 1.0.756 includes a postinstall.js script that triggers on npm install on Windows platforms. This script downloads a ZIP file from https://files.catbox.moe/rp8idk.zip, extracts it to a randomized temporary directory using PowerShell's Expand-Archive, and then executes a bundled pythonw.exe with exec_.py as the script. The execution is detached, hidden, and ignores standard IO, allowing the payload to run silently and persist beyond the npm process. This behavior is indicative of an alternate-runtime dropper pattern, where an opaque remote payload is executed with the installer's privileges, posing a significant security risk. The package claims to provide Roblox-TS service utilities but has no legitimate need for this behavior, confirming its malicious intent.

References

npmjs.com/package/@rbxst/services/v/1.0.756 (opens in a new tab)

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What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Aug 2026, 15:37 UTC

Technical details

References

Community reviews