#claude-code

China's Ministry of Industry and Information Technology (MIIT) issued a risk notice on July 8, 2025, warning that Claude Code versions 2.1.91 through 2.1.196 contain a backdoor that secretly transmits users' location and identity information to remote servers without consent. This is significant because Claude Code is a widely used AI coding tool, and the backdoor compromises the privacy and security of many developers. The authoritative warning from a government body like MIIT underscores the severity of the threat and may prompt organizations to reassess their use of AI tools in development pipelines. The affected versions span from 2.1.91 to 2.1.196, and the backdoor includes a built-in monitoring mechanism that exfiltrates sensitive data. Users are advised to immediately check, uninstall the vulnerable versions, or upgrade to the latest secure version that has removed the malicious code, and to strengthen outbound permission controls and traffic monitoring for development tools.

Anthropic's Claude Code version 2.1.91 includes obfuscated code that checks for Chinese timezones and proxy URLs, then encodes region information into prompts sent to the API without disclosure in changelogs. This raises serious concerns about user privacy and transparency in AI tools, as it could be used to identify unauthorized usage or model distillation without user consent, potentially undermining trust. The detection logic uses XOR obfuscation with key 91 to check for timezones Asia/Shanghai or Asia/Urumqi, and proxy URLs pointing to Chinese domains or AI labs; region data is encoded by altering the system prompt's date format and Unicode apostrophe.