Huntress observed a campaign in late September in which attackers stand up Custom GPTs — personalised ChatGPT variants hosted on the legitimate ChatGPT site — named to look like product offerings, including one called "Plus 5.6", and reach victims through sponsored Google search results for terms such as "chatgpt". The Custom GPT answers prompts with a Google Sites link framed as a backup domain for "limited availability"; the linked page presents a fake Cloudflare CAPTCHA, which is the ClickFix step that talks the victim into copying and running a PowerShell command. That command deploys an MSI installer, ISOSimple.msi, which runs a DLL sideloading chain abusing a legitimate Canon-signed binary to load shellcode, install a persistence script and launch a RAT. Huntress says at least 40 users were infected. It is the latest instance of attackers borrowing a trusted AI platform's surface — earlier campaigns used shared chatbot conversations and malicious Claude artifacts — and it needs no vulnerability in the platform itself.

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