Assess Before You Touch Anything
Microsoft Data Security Index (Jan 2026) reports that "40% of enterprise data-security incidents are linked to AI systems, up from 27% the prior year." Use that as the why-now opener for assessment, not as a substitute for your own tenant evidence. This is Microsoft-commissioned survey data, not an independent study.
What You Do
Tools In This Phase
Copilot Readiness report; Purview DSPM for AI; SharePoint Advanced Management Data Access Governance; Defender for Cloud Apps Cloud Discovery; Secure Score. Use a third-party assessment tool only if native reporting cannot support the delivery motion you need.
People
Lead: AI owner with the tenant/M365 admin. Accountable: executive sponsor or your partner principal. Consulted: security/compliance owner and delivery consultant. Informed: helpdesk and champion leads.
Process
Inventory first, interpret second, act later. The point of this phase is to establish the before-state and decide where the risk is concentrated before anyone starts changing permissions or labels.
Quotable
"Data oversharing is the single largest data security risk that organizations face when deploying Microsoft 365 Copilot" (Zero Trust Workshop AI_047).
Done When
You have a dated before-state: overshared sites, EEEU-configured sites, anonymous links, stale guests, unlabeled sensitive data, Secure Score, label coverage, and GenAI app inventory. Leadership has approved the first risk priorities and knows which findings are limited by license depth.
Ready For Next Phase
Move forward only when the team can name the first sites/users/apps to contain and has preserved the evidence needed to prove the before/after delta.
Capture
Exposure heat map, tool-selection memo, scan time-on-task, screenshots, first list of "we need to fix this before scale" items.