Restrict Copilot web search, agents and third-party AI providers

Description

Microsoft 365 Copilot settings follow a decision recorded by the organization (data protection officer and security team) and, by default in this profile:

• Web search (web grounding in Microsoft 365 Copilot and Copilot Chat) is turned off, or limited to groups whose use case was assessed;
• agents: access is limited to selected groups, sharing agents with the entire organization is limited to administrators, and only agents built by the organization or approved in Integrated apps can be installed;
• AI providers operating as Microsoft subprocessors (such as Anthropic models) are off until an assessment covers data location and processing terms;
• self-service trials and purchases of Copilot are not allowed.

This control is drawn from the ASD Blueprint and will be revisited when CIS or SCuBA publish Copilot rules. Copilot Studio agents are covered in the POWER domain, agent identities in the APPS domain.

Rationale

Web grounding sends generated search queries, derived from prompts and work content, to Bing, outside the Microsoft 365 service boundary. Third-party model providers process prompts under separate terms, which matters under GDPR and for data sovereignty. Agents and their connectors act with the user's permissions and can reach external services. Each of these features widens where work data goes, so it should be enabled by decision, not by default.

Impact

Users lose web answers in Copilot and access to agents that are not approved; they request them. Copilot features change often: review these settings at each major announcement.

Applies when

Requires: Microsoft 365 Copilot

Audit

1. Sign in to the Microsoft 365 admin center (https://admin.cloud.microsoft) as at least a Global Reader (AI Administrator for Copilot settings).
2. Browse to Copilot > Settings and open:
   • Web search: check how web search is controlled (the Cloud Policy setting Allow web search in Copilot in the Microsoft 365 Apps admin center, https://config.office.com) and that it is disabled or scoped to assessed groups;
   • Data access > AI providers operating as Microsoft subprocessors: third-party providers are disabled;
   • User access > Microsoft 365 Copilot self-service purchases: Do not allow.
3. Browse to Agents > Settings (or Copilot > Agents): Allowed agent types, Sharing and User access are limited as described.
4. Browse to Settings > Integrated apps and check that each available agent is approved.
5. Fail if any of these settings is open to all users without a recorded decision.

Remediation

1. With an AI Administrator or Global Administrator, record the organization's decision for each feature.
2. In the Microsoft 365 Apps admin center (https://config.office.com) > Customization > Policy Management, create or edit a policy with Allow web search in Copilot set to Disabled (or enabled only for an assessed group), with an Office Apps Administrator.
3. In the Microsoft 365 admin center, Copilot > Settings > Data access, disable the third-party AI subprocessors; User access, set self-service purchases to Do not allow.
4. In Agents > Settings, limit allowed agent types to those built by the organization and approved ones, sharing to administrators, and access to selected groups.
5. Block or remove unapproved agents in Settings > Integrated apps.

Rollback

Re-enable the features in the same pages.

References

• Configure Microsoft Copilot settings in the Microsoft 365 admin center Microsoft, vendor-doc, accessed 2026-10-24
• Manage web search in Microsoft 365 Copilot and Copilot Chat Microsoft, vendor-doc, accessed 2026-10-24
• Manage agents for Microsoft 365 Copilot in the Microsoft 365 admin center Microsoft, vendor-doc, accessed 2026-10-24
• ASD's Blueprint for Secure Cloud, Copilot settings Australian Signals Directorate, guide, accessed 2026-10-24

Mappings

How this control relates to the other framework's: equivalent, stricter, looser, partial or related.

Related controls

• related CB-M365-POWER-022 Require user authentication for Copilot Studio agents and limit how widely they are shared
• related CB-M365-APPS-018 Block high-risk AI agents with Conditional Access
• related CB-M365-APPS-019 Govern AI agent identities (ownership, sponsors, credentials and privileges)
• related CB-M365-POWER-024 Govern the lifecycle of Copilot Studio agents
• related CB-M365-DATA-004 Enforce a DLP policy for Microsoft 365 Copilot

People and lifecycle