Malicious VS Code Extensions with 1.5 Million Installs Steal Developer Data
- Securityish
- Threats & Incidents
Quick Summary
Cybersecurity researchers have uncovered two malicious Visual Studio Code (VS Code) extensions, with a total of 1.5 million installs, that secretly exfiltrate developer source code to servers in China. The extensions, named ChatGPT – 中文版 and ChatGPT – ChatMoss, capture every file opened and modification made without user consent. This incident raises significant concerns regarding the security and privacy of developers using these tools, as they operate normally while conducting covert data theft.
The Securityish Brief
Researchers from Koi Security discovered two malicious Microsoft Visual Studio Code (VS Code) extensions that masquerade as AI-powered coding assistants. These extensions, ChatGPT – 中文版 (1,340,869 installs) and ChatGPT – ChatMoss (151,751 installs), have a combined total of 1.5 million installs and are still available on the Visual Studio Marketplace. They are designed to capture every file opened and any source code modifications, sending this data to servers located in China without the users’ knowledge.
The malicious code within these extensions operates seamlessly, providing autocomplete suggestions and error explanations, which helps avoid raising suspicion among users. The spyware infrastructure is identical in both extensions, indicating a coordinated effort to siphon off sensitive developer data.
Upon opening a file or making edits, the extensions encode the contents in Base64 format and transmit it to a server identified as “aihao123[.]cn.” Additionally, they feature a real-time monitoring capability that can exfiltrate up to 50 files from a user’s workspace. A hidden iframe also loads analytics SDKs from Chinese companies, further enhancing the tracking of user behavior.
Implications for Developers and Organizations
This incident highlights the growing risks associated with third-party extensions in development environments. Developers should be particularly cautious when installing tools that require extensive permissions or access to their code. The fact that these malicious extensions function as advertised makes it difficult for users to identify them as threats.
Organizations must ensure that their development teams are aware of the potential risks posed by malicious extensions and should consider implementing stricter controls over software installations. Regular audits of installed extensions and monitoring for unusual activity can help mitigate the risks associated with such threats.
Furthermore, the discovery of vulnerabilities in JavaScript package managers, collectively named PackageGate, underscores the importance of maintaining robust security practices in software development. Developers should disable lifecycle scripts and commit lockfiles to protect against supply chain attacks.
- ChatGPT – 中文版: This extension has 1,340,869 installs and captures developer data without consent.
- ChatGPT – ChatMoss: With 151,751 installs, this extension also exfiltrates sensitive information to China-based servers.
Key Takeaways
- Review and audit all installed VS Code extensions to ensure they are from trusted sources.
- Monitor your development environment for any unusual file access or modifications.
- Disable lifecycle scripts and commit lockfiles in your JavaScript package managers to enhance security.
- Educate your development team about the risks of using third-party extensions and tools.
- Consider implementing stricter controls over software installations within your organization.
Key Terms & Concepts
- Base64: Base64 is a method of encoding binary data into ASCII characters, often used for transmitting data over media designed to deal with text.
- SDK: An SDK, or Software Development Kit, is a collection of software tools and libraries that developers use to create applications for specific platforms.
- Spyware: Spyware is malicious software designed to gather information from a computer or network without the user’s knowledge.
- Supply Chain Attack: A supply chain attack targets vulnerabilities in third-party services or software to compromise a system.
Read the original article here: https://thehackernews.com/2026/01/malicious-vs-code-ai-extensions-with-15.html
Your 5-Minute Securityish Brief
A weekly digest of cybersecurity news, phishing alerts, privacy tips, and emerging threats, simplified so anyone can understand what matters and why.
Securityish
Securityish explains cybersecurity, scams, data breaches, and privacy risks in simple language so you know what’s happening and how to protect yourself.
© 2026 Securityish
