Check 1
Who holds Modify All Data?
Setup path: Quick Find box, type Permission Sets, then open Permission Sets. Open a set and click App Permissions or System Permissions to read what it grants.
Salesforce calls Modify All Data "the highest level of data access". It overrides all sharing rules and object-level permissions. The first query lists every active user who holds it, from a profile or a permission set. Profiles show up because each profile keeps its permissions in a permission set it owns (IsOwnedByProfile = true).
SELECT AssigneeId, PermissionSet.Name, PermissionSet.IsOwnedByProfile FROM PermissionSetAssignment WHERE PermissionSet.PermissionsModifyAllData = true AND Assignee.IsActive = true SELECT PermissionSetGroupId FROM PermissionSetAssignment WHERE PermissionSetGroupId IN ( SELECT PermissionSetGroupId FROM PermissionSetGroupComponent WHERE PermissionSet.PermissionsModifyAllData = true OR PermissionSet.PermissionsViewAllData = true) AND Assignee.IsActive = true
Swap PermissionsModifyAllData for PermissionsViewAllData to find who can read every record. The second query finds permission set groups, assigned to active users, that include either permission.
Sources: Modify All Data Permission in Salesforce (Salesforce Help); PermissionSet object reference (Salesforce Developers); PermissionSetAssignment object reference (Salesforce Developers).