GoKawiil
Tech News
Security researchers discovered a fake extension on Cursor's marketplace designed to impersonate a Claude Code tool and give attackers persistent access to developers' computers. The extension was distributed through Cursor's official marketplace, exploiting trust in the platform to reach developers using AI coding assistants.
A tampered version of Anthropic's Claude Code VS Code extension, labeled version 2.1.313, was available on Cursor's extension marketplace for about 11 hours on October 29, reaching as many as 5,000 developers. Security researchers at Phorion and OpenSourceMalware found the attackers inserted malicious JavaScript into the extension's main file that ran automatically on load, without any user interaction with Claude Code.
Security firm Phorion identified that version 2.1.313 of the official Claude Code extension for VS Code, distributed via the Cursor Marketplace, contained a hidden SSH backdoor targeting macOS, Linux, and Windows systems. Cursor has since removed the affected release from its marketplace and pulled the corresponding NPM and VS Code packages from their registries.