Incident database

New Windows malware CLOSEDQUORUM uses LLMs to pick post-compromise actions

Cisco Talos discovered a Windows malware strain, CLOSEDQUORUM, that queries four LLM providers (Gemini, DeepSeek, Qwen, Mistral) to autonomously vote on post-compromise actions such as credential theft, code injection, and persistence, without needing further human operator commands. Talos has not observed any in-the-wild deployment of the malware.

Disclosed 22 September 2026 · Record updated 1 October 2026

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Vulnerabilities

Windows malware lets four AI models vote on its next move

Cisco Talos says CLOSEDQUORUM delegates post-compromise decisions to a quorum of large language models, though it has not seen the malware deployed in the wild.

23 Sept 2026