Your security architect raises a concern: if a computer-use agent visits a malicious website during an automated session, could malware on that site compromise your corporate network? Which design feature of Copilot Studio computer use specifically addresses this threat?

Copilot Studio's computer use feature provisions hosted machines (virtual machines) in Microsoft's cloud infrastructure. These machines are isolated sandboxes — they are not joined to the corporate domain and have no direct network path to internal corporate resources by default. This network isolation is the primary defense against threats from malicious websites visited during a computer use session.

Additionally, the hosted machine environment is ephemeral — it is reset to a clean baseline image after each session. Any malware, cookies, or artifacts from a session are wiped when the session ends, preventing persistence of threats.

Option A (read-only browser profile blocking downloads) — while some configurations may restrict downloads, this is not the primary security isolation mechanism and is not the defining architectural feature.

Option C (Defender for Endpoint monitoring) — while Defender may be present in hosted environments, this is not the architectural isolation feature that addresses the corporate network compromise concern.

Option D (blocking external websites by default) would make computer use useless for most web automation scenarios. External site access is the entire point.

Exam security principle for computer use: sandbox isolation + session reset = key security properties. The hosted machine is not on the corporate network; the session environment is ephemeral. These two properties together address the network compromise threat.