'Prompt Poaching': Malicious Extensions Harvest AI Chat Data, Threatening Privacy and Security

March 28, 2026
'Prompt Poaching': Malicious Extensions Harvest AI Chat Data, Threatening Privacy and Security
  • Secure Annex reports show Chrome extensions mimicking legitimate tools secretly collecting user prompts and AI responses via API interception or DOM scraping.

  • Dozens of incidents have been documented where Chrome extensions covertly gather AI usage data through methods like DOM scraping or API interception and send stolen conversations to attacker-controlled servers.

  • Security teams emphasize identifying workflow gaps that push users toward unsafe extensions and monitoring for suspicious activity to reduce reliance on risky tools.

  • Collected data can include corporate data and PII, creating regulatory, financial, and reputational risks for organizations and individuals.

  • Overall, prompt poaching highlights the need for vigilant security practices as AI tools become more integrated into daily workflows.

  • Extensions with broad permissions can read page content, monitor activity across tabs, and interact with other tabs, turning legitimate productivity tools into data exfiltration channels.

  • A new attack vector called 'prompt poaching' involves malicious browser extensions that covertly harvest AI chat data by monitoring AI-related browser sessions and exfiltrating prompts and responses in real time.

  • Risks are heightened in enterprise environments where stolen AI conversations could reveal IP, internal communications, or customer data, with attackers potentially reusing data for targeted phishing or underground sales.

  • Mitigations include restricting installation of unapproved extensions, enforcing policies via browser management tools, using official AI tools from trusted vendors, scrutinizing permissions, and auditing installed extensions for unusual outbound connections.

  • Threat actors often use supply-chain or clone-and-modify strategies, duplicating legitimate extensions or compromising popular ones to harvest conversations without user awareness.

  • In at least one case, a legitimate extension was retrofitted with AI conversation harvesting capabilities after deployment, affecting existing users.

  • As AI adoption grows, the attack surface expands, underscoring the need for stricter controls and awareness around browser-based AI integrations.

Summary based on 2 sources


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Sources

Malicious Browser Extensions Hijack Users’ AI Chats in New “Prompt Poaching” Attack

GBHackers Security | #1 Globally Trusted Cyber Security News Platform • Mar 28, 2026

Malicious Browser Extensions Hijack Users’ AI Chats in New “Prompt Poaching” Attack

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