Several ChatGPT-related browser extensions published under “ChatGPT Mods” have been identified as potentially malicious due to excessive permissions, content injection, and lack of transparency.

While marketed as productivity tools, these extensions introduce serious security and privacy risks.

Technical overview of the risk

Browser extensions operate with elevated privileges. Depending on permissions granted, they can:

• Inject JavaScript into ChatGPT pages

• Read and alter DOM content

• Capture keystrokes and clipboard data

• Access authentication cookies

• Transmit data to third-party servers

This effectively makes them man-in-the-browser tools.

Key red flags identified

• Identical or near-identical codebases across multiple extensions

• Overuse of host_permissions

• No open-source repository or audit trail

• Vague or missing data-handling disclosures

This pattern is commonly associated with extension-based data harvesting.

Attack vectors

Possible exploitation includes:

• Session hijacking via cookie access

• Prompt and conversation scraping

• Credential exposure through clipboard monitoring

• Unauthorized API key extraction

These attacks require no user interaction after installation.

Immediate remediation steps

• Remove all extensions published by ChatGPT Mods

• Invalidate active sessions by logging out

• Rotate passwords and API keys where applicable

• Review browser extension permissions

• Clear site data for chat.openai.com

Best practices going forward

• Principle of least privilege for extensions

• Prefer built-in ChatGPT functionality

• Use extensions with open-source code and reputable maintainers

• Periodically audit installed extensions

Conclusion

Browser extensions should be treated as privileged software, not harmless add-ons. Any extension that can read web content can access sensitive business and personal data.

Security awareness at the browser level is now a professional requirement.