Claude Cowork shifts tasks to cloud by default

Moving execution cloud-side is a sensible containment upgrade, but it shifts trust from the endpoint to Anthropic’s infrastructure and still leaves prompt injection as the core agentic risk.

• –Cloud sandboxes are temporary, tenant-isolated, network-restricted, and use short-lived credentials
• –Local files remain reachable through the Claude Desktop app when connected folders are authorized
• –Browser control has no sandbox between Claude and visible applications, making signed-in sites especially sensitive
• –Plugins and local MCP servers can expand Cowork’s permissions and attack surface
• –Developers should treat unattended tasks as production automation: minimize access, require approvals, and review outputs