Fake ChatGPT Downloads Hide Yoba Malware

Attackers used GitHub and search results to promote counterfeit ChatGPT and Claude desktop downloads. The ZIP files bundled real signed OpenAI or Anthropic executables with malicious files, tricking Windows users into launching malware that can persist on the device and install a cryptocurrency miner.

Key findings

• Attackers promoted fake GitHub repositories and GitHub Pages sites offering supposed desktop versions of ChatGPT and Claude.
• Some malicious projects appeared prominently in Google Search results, consistent with SEO poisoning.
• The counterfeit ZIP archives combined signed OpenAI or Anthropic Setup.exe files with malicious DLL files.
• Launching the installer triggered DLL sideloading, allowing malicious code to run alongside a legitimate signed executable.
• Yoba established persistence through a scheduled task disguised as a Windows Media Player operation and ultimately deployed the XMRig cryptocurrency miner.

Who’s being targeted

• Commonly targeted roles: All Windows users, Employees using AI tools, Developers, IT professionals, Help desk teams, Security operations teams.
• Affected industries: Organizations using AI tools, Information technology, Professional services, Education, All Windows-based organizations.
• Attack channels: website.
• Impersonated: OpenAI or Anthropic.

Awareness takeaways

• Download AI software only from approved, official distribution channels, not from search results, GitHub projects, or promotional download pages.
• Do not treat a signed installer or familiar brand as proof that an entire download is safe.
• Avoid approving administrator prompts for software downloaded from an unverified source; report the download to IT or security instead.
• If a fraudulent installer may have run, report it immediately so security can isolate and investigate the device rather than simply deleting the visible miner.

Red flags to watch for

• The software is offered through an unofficial GitHub repository or GitHub Pages site.
• The product name suggests an unverified or unusually new release, such as GPT-6 Astra.
• A ZIP archive contains extra files alongside a supposedly legitimate installer.