Fake LLM Portal Steals Access Tokens

Help Net Security · High sophistication
Last updated November 3, 2026

Researchers found that criminals are stealing cloud and AI access, then reselling it through illicit AI services while victims receive enormous cloud bills. In one documented case, a group used a fake portal for LLM users to trick visitors into submitting information containing active access tokens, bypassing passwords and multi-factor authentication.

Key findings

  • Mandiant investigated LLMJacking incidents affecting financial services, retail, technology, and transportation organizations across the Americas and Asia Pacific.
  • Attackers used stolen AI access to generate cloud charges exceeding $100,000 per day; some victims faced bills of up to $1 million.
  • UNC6993 operated a fake LLM-user portal that tricked visitors into submitting data containing active access tokens.
  • The stolen tokens allowed attackers to bypass passwords and MFA, access AI APIs, and resell the victim organization's AI capacity.
  • Attackers may make very small test requests to stolen API keys to confirm they work without triggering security alerts.

Who’s being targeted

  • Commonly targeted roles: Developers, AI/ML engineers, Cloud administrators, DevOps teams, Data scientists, Engineering managers, Security operations teams.
  • Affected industries: Financial services, Retail, Technology, Transportation.
  • Attack channels: website.
  • Impersonated: A legitimate group or community for LLM users.

Awareness takeaways

  • Never paste API keys, session tokens, or connection data into an unapproved website, even if it claims to offer access to an AI community or service.
  • Treat API keys and active session tokens like passwords: protect them from public code repositories and revoke them immediately if exposed.
  • Report unexpected AI-service activation or unusual usage immediately, because costs can escalate in minutes or hours.

Red flags to watch for

  • The portal asks for an active access token rather than using an approved sign-in method.
  • A community or enrollment page requests sensitive connection data.
  • The site is not an approved company or vendor portal.
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Read the video transcript

“Join our group of LLM users.” Sounds useful, right? UNC6993’s fake portal asked visitors to paste connection data. Hidden inside: an active access token. That token can bypass your password and MFA. Here’s the giveaway: a community signup wants your token, not approved sign-in. Stolen access can run AI APIs and rack up over $100,000 a day. If a website asks you to paste an API key or token, stop. Don’t paste it.

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