Cursor removes malicious Claude Code extension after SSH backdoor attempt
A malicious version of Anthropic’s Claude Code extension distributed through the Cursor marketplace attempted to install a persistent Secure Shell (SSH) backdoor on developers’ machines, potentially giving attackers remote access to systems holding source code, credentials and other sensitive information. “Between about 2:27am PT and 1:35pm PT today, a maliciously modified version of Anthropic’s Claude Code extension was made available in the Cursor VS Code Extension Marketplace,” Cursor said in a security notice . Cursor removed the compromised versions, 2.1.312 and 2.1.313, after discovering they had been available in its VS Code extension marketplace for approximately 11 hours on October 29. The company said the malicious code attempted to add an attacker-controlled SSH key, enable local SSH access, and establish a reverse tunnel to an attacker-controlled server. “These malicious versions of the extension were not developed by Anthropic,” Cursor added in the notice. The affected ver