---
title: Tip: a real signature on Setup.exe doesn't make the ZIP safe. Get AI desktop apps only from the vendor's own site, and treat any extra DLL next to a signed installer as a red flag | ctxsec
url: https://ctxsec.com/items/tip-signed-exe-is-not-a-safe-installer-check-the-dlls
description: ""
status: "guidance (based on Check Point Research, Oct 27)"
published: 2026-10-27
---

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[← Tips & Guides](/tips) · [markdown](/items/tip-signed-exe-is-not-a-safe-installer-check-the-dlls.md)

guidance (based on Check Point Research, Oct 27)

2026-10-27

### Tip: a real signature on Setup.exe doesn't make the ZIP safe. Get AI desktop apps only from the vendor's own site, and treat any extra DLL next to a signed installer as a red flag

The [Yoba campaign](/items/hunt-yoba-fake-chatgpt-claude-desktop-signed-setup-sideload) ships genuine, validly signed OpenAI and Anthropic installers. The malware is a separate DLL in the same folder that Windows loads first. A signature check on the EXE passes, and many antivirus tools stay quiet.

1. Download ChatGPT, Claude, Cursor and similar desktop apps only from the vendor's own domain or a store you trust, never from a GitHub Pages site or a search ad, however high it ranks. OpenAI and Anthropic do not publish "free desktop" builds on random GitHub accounts.
2. Before you run any installer that came in a ZIP, look at what else is in the folder. Files like `winmm.dll`, `version.dll` or `d3dx9_*.dll` sitting next to a Setup.exe are a classic sideloading setup.
3. Be suspicious when an "app" demands admin rights just to start.
4. On managed machines, use app control rules (for example WDAC or AppLocker) so programs in Downloads and Temp can't load unsigned DLLs, and alert on scheduled tasks that claim Microsoft as author but point to ProgramData.

Sources: [Check Point Research: Tricks from the Past deployed via signed ChatGPT and Claude binaries (Oct 27)](https://research.checkpoint.com/2026/tricks-from-the-past-deployed-via-signed-chatgpt-and-claude-binaries/)