Custom GPT Exploitation: How Threat Actors Weaponized AI Platforms for RAT Delivery in 2026
In September 2026, threat actors launched a sophisticated ClickFix campaign exploiting OpenAI's Custom GPT feature to deliver remote access Trojans (RATs). Attackers created malicious Custom GPTs mimicking legitimate ChatGPT releases, leveraging trusted domains from OpenAI and Google to deceive victims. The attack chain began when users interacted with fake Custom GPTs named "Plus 5.6" through the official ChatGPT domain, then redirected to a Google Sites page with fake CAPTCHA prompts. Victims were tricked into executing PowerShell commands that downloaded MSI files, which used legitimate Canon-signed applications to sideload malicious DLLs and deploy RATs capable of data theft, surveillance, and network infiltration. Huntress security researchers documented at least 40 confirmed incidents from this campaign. This attack represents an evolution in social engineering tactics, exploiting trust in AI platforms and legitimate cloud infrastructure to bypass traditional security awareness training focused on domain verification.
Kill Chain
