SC-401 Administering Information Security in Microsoft 365 Questions and Answers

Step 1 – Requirement

We need a custom sensitive information type (SIT) that detects:

An employee ID number in a specific format → hire date + three digits.

This is a pattern-based requirement.

Specific keywords within 300 characters of that ID → “Employee”, “ID”, or “Identification”.

This is a keyword proximity requirement.

Step 2 – Sensitive info type elements in Microsoft 365

When creating custom SITs, you define primary and secondary elements:

Primary element → The main pattern or data to detect (the most defining factor).

Secondary element → Supporting evidence that must be found near the primary element to increase confidence.

Available elements:

Regular expression → Used to define patterns such as date + digits (for employee ID).

Keyword list → Used for lists of words/phrases like " Employee " , " ID " , " Identification " .

Functions → Used for built-in validators like credit card checksum, not relevant here.

???? Reference: Create a custom sensitive information type in Microsoft 365

Step 3 – Apply to scenario

Employee ID pattern (hire date + 3 digits) → Needs a regular expression → This must be the Primary element.

Keywords (“Employee”, “ID”, “Identification”) within 300 characters → A keyword list → This must be the Secondary element.

This question is about creating a one-click policy within Microsoft Purview ' s Data Security Posture Management for AI portal. These policies are designed to mitigate risks associated with sensitive data and AI websites. The correct configuration for this specific scenario is to select " Test it out first " and apply the policy to " Devices, Instances, and SharePoint sites. " This configuration is based on Microsoft ' s recommended practices for deploying data loss prevention (DLP) and similar policies.

Policy Mode: " Test it out first "

Microsoft recommends using test mode for new policies to evaluate their impact and effectiveness before enforcing them. This approach prevents unintended disruptions to user workflows. In test mode, the policy monitors and audits the specified activities without blocking them. It generates alerts and reports, allowing administrators to review the policy ' s behavior and make necessary adjustments. This aligns with the principle of " start small, then scale, " ensuring that a policy designed to block sensitive data transfers doesn ' t inadvertently prevent legitimate business activities.

Policy Scope: " Devices, Instances, and SharePoint sites "

The policy aims to block users from pasting or uploading sensitive data to AI websites. This requires a comprehensive scope to cover all potential data exfiltration points.

Devices: This covers the user ' s local device, preventing data from being uploaded or pasted from applications running on the machine. This is crucial for controlling data from endpoints.

Instances: This refers to SaaS (Software as a Service) instances, including AI websites. Applying the policy to instances ensures that data transfers to these external services are monitored and controlled.

SharePoint sites: Data residing in SharePoint is a common source of sensitive information. Including SharePoint sites in the policy scope ensures that data cannot be directly copied from these locations and uploaded to AI websites, providing a holistic security posture.

By selecting " Devices, Instances, and SharePoint sites, " the policy is configured to monitor and protect data across the most common sources and destinations, providing a robust defense against data exfiltration to AI services. This comprehensive approach is a cornerstone of modern data security strategies in Microsoft 365.

This information is verifiable through Microsoft ' s official documentation for Microsoft Purview, particularly sections related to Data Loss Prevention (DLP) policies and Data Security Posture Management for AI. The best practice of " test first " and the broad scope for sensitive data protection are consistently recommended.

To add a new keyword dictionary in Microsoft Purview Data Loss Prevention (DLP), you must create a Sensitive Information Type (SIT).

Sensitive Info Types (SITs) allow you to define custom detection rules, including keyword dictionaries, regular expressions, and functions for identifying sensitive content in emails, documents, and other Microsoft 365 locations. A keyword dictionary is a list of predefined words/phrases that Microsoft Purview can use to identify and classify content for DLP policies.

Steps to add a keyword dictionary:

1. Go to Microsoft Purview compliance portal

2. Navigate to Data classification > Sensitive info types

3. Create a new sensitive info type

4. Add a keyword dictionary

5. Save and use it in a DLP policy

To meet the requirement that all administrative users must be able to create Microsoft 365 sensitivity labels, we need to assign the Sensitivity Label Administrator role to the correct users.

Sensitivity Label Administrator Role Responsibilities

This role allows users to:

● Create and manage sensitivity labels in Microsoft Purview.

● Publish and configure auto-labeling policies.

● Modify label encryption and content marking settings.

Review of Admin Roles from the Table:

Users that must be assigned the Sensitivity Label Administrator role:

● Admin2 (Compliance Data Administrator)

● Admin3 (Compliance Administrator)

● Admin1 (Global Reader) (should be assigned this role to fulfill the requirement that all admins can create labels).

The requirement states that all Microsoft 365 data for users must be retained for at least one year. In Microsoft 365, retention policies must be configured for each type of data storage.

Step 1: Identifying Where Data is Stored

From the case study, users store data in the following locations:

● SharePoint Online sites

● OneDrive accounts

● Exchange email

● Exchange public folders

● Teams chats

● Teams channel messages

Since these locations fall under two broad categories:

● Microsoft Exchange data (Emails, Public folders)

● SharePoint, OneDrive, and Teams data

Step 2: Required Retention Policies

1️. A single retention policy can cover:

● SharePoint Online

● OneDrive

● Microsoft Teams

2. A second retention policy is required for:

● Exchange (Emails & Public Folders)

Thus, the minimum number of retention policies required to meet the requirement is 2.

Microsoft 365 retention policies can be applied broadly across multiple services with just two policies:

● One for Exchange & Public Folders

● One for SharePoint, OneDrive, and Teams

There ' s no need for separate policies for each individual workload unless different retention durations are required, which is not stated in the requirement.

Understanding Site4 ' s Retention Policies:

● Site4RetentionPolicy1 deletes items older than 2 years from creation. If a file was created on January 1, 2021, it would be deleted after January 1, 2023.

● Site4RetentionPolicy2 retains files for 4 years from creation. If a file was created on January 1, 2021, it will be kept until January 1, 2025, but not deleted after that (policy states " Do nothing " ).

Statement 1 - Yes, because Site4RetentionPolicy2 ensures files are retained for 4 years.

Statement 2 - Yes, because Site4RetentionPolicy2 retains the file for 4 years (until January 1, 2025).

Statement 3 - No, because retention is only for 4 years (until January 1, 2025). After that, the policy does " nothing, " meaning the file is no longer recoverable after that period.

Understanding DLP Policy Impact on File Access

The DLP policy (DLPpolicy1) applies to Site2 and restricts access when:

● Content contains SWIFT Codes.

● Instance count is 2 or more.

File Analysis (Based on SWIFT Codes Count)

Files that remain accessible (not restricted by DLP):

● File1.docx (Contains only 1 SWIFT Code → Below restriction threshold)

User access after DLP policy is applied:

User1 (Site Owner):

● Has higher privileges and can override DLP restrictions (through admin intervention).

● Can access 2 files (File1.docx + override access to another file).

User2 (Site Visitor):

● Has read-only access but DLP blocks access to restricted files.

● Can only access 1 file (File1.docx), since all others are restricted.

The goal is to automatically label documents in Site1 that contain credit card numbers. To achieve this, we need a sensitivity label with an auto-labeling policy based on a sensitive info type that detects credit card numbers.

Step 1: Create a Sensitive Info Type

● A sensitive info type is needed to detect credit card numbers in documents.

● Microsoft Purview includes built-in sensitive info types for credit card numbers, but we can also create a custom one if necessary.

Step 2: Create a Sensitivity Label

● A sensitivity label is required to classify and protect documents containing sensitive information.

● This label can apply encryption, watermarking, or access controls to credit card data.

Step 3: Create an Auto-Labeling Policy

● An auto-labeling policy ensures that the sensitivity label is applied automatically when credit card numbers are detected in Site1.

● This policy is configured to scan files and automatically apply the correct sensitivity label.

To detect and protect confidential documents, we need a custom rule to identify project codes that start with 999 (since they are classified as confidential).

Box 1: A Sensitive Info Type (SIT) allows Microsoft Purview DLP policies to recognize structured data (e.g., project codes). DLP policies require a sensitive info type to detect content based on patterns, keywords, or dictionary terms. A sensitivity label alone does not define detection logic—it is used for classification and protection after content is identified.

Box 2: Since project codes follow a structured 10-digit pattern, we should use a Regular Expression (Regex) to match project codes that start with 999.

Example Regex pattern:

999\d{7}

This pattern detects a 10-digit number starting with " 999 " .

In Microsoft Purview Data Lifecycle Management, different Microsoft 365 locations require separate retention policies because they fall under different storage and compliance models.

Teams Chats & Teams Channel Messages (1 Policy) require a separate retention policy because Teams messages are stored differently than Exchange and SharePoint content. One policy can cover both Teams chats and Teams channel messages. Exchange Email (1 Policy) requires its own separate policy since emails are managed differently than Teams or SharePoint content. SharePoint Sites & Microsoft 365 Groups (1 Policy) are both stored in SharePoint Online, so they can be managed under one policy.

Step 1 – Requirement

You want to create a custom sensitive info type named Sensitive1.

This SIT will be created from a document fingerprint of Template1.docx.

You then want to use Sensitive1 in DLP policies.

Step 2 – Where do you create custom Sensitive Info Types?

Custom SITs (including document fingerprinting) can only be created in the Microsoft Purview compliance portal.

They cannot be created in the Exchange admin center, SharePoint admin center, or directly in PowerShell.

Answer for creation: The Microsoft Purview portal

Step 1 – Scenario

A user named User1 was a member of a dynamic security group (Group1).

User1 is no longer a member of that group.

You need to determine why User1 was removed by searching the audit log.

Step 2 – How group membership changes are logged in Microsoft 365 audit logs

Microsoft 365 audit logs record group membership activities in Azure AD. The most relevant activities for a user disappearing from a group are:

Removed member from group – Directly indicates that a user was removed from a group.

Updated group – Logged when group properties or membership rules (for dynamic groups) are modified. If Group1 is a dynamic group, changes to membership rules could have caused User1 to no longer qualify, and this would appear as an Updated group event.

Step 3 – Why not other options

Deleted user / Deleted group: Would mean the entire user or group object was deleted, not just removal.

Changed user password, Reset user password, Set license properties, Changed user license: These are account-related, not group membership-related.

Added member to group: The opposite action.

Step 4 – Microsoft Reference

From Microsoft documentation:

Audit logs include events such as when a member is added or removed from a group, and when group properties or membership rules are updated.

An activity policy in Microsoft Defender for Cloud Apps (Microsoft Defender portal) allows you to track and alert on specific user actions, such as sharing sensitive documents externally from OneDrive. This policy can detect file-sharing activities and send alerts when files are shared with external users, which meets the requirement.

for each of the following you can have a retention policy

1.EXO, SPO, ODfB, M365 groups

2.Teams channel messages, teams chat

3.Teams private channel messages

To ensure Azure Storage Account keys are encrypted when sent via email, you need a Data Loss Prevention (DLP) policy that detects Azure Storage Account keys using a sensitive information type and automatically encrypts emails containing these keys.

A DLP policy with Exchange email as the only location meets this requirement because it identifies sensitive data in email messages and it applies protection actions, such as encryption, blocking, or alerts.

Let’s analyze each scenario based on the given retention policies and Microsoft 365 documentation.

???? Policies Recap

Policy1

Teams channel messages → All Teams → Retain 7 years → Delete automatically.

Teams chats → User1 → Retain 7 years → Delete automatically.

Policy2

Teams channel messages → Team1 → Retain 5 years → Delete automatically.

Teams chats → User2 → Retain 5 years → Delete automatically.

???? Reference: Retention policies in Microsoft Teams

???? Statement 1: The message edited by User1 will be deleted after five years.

Location = Team1 channel.

Policy1 applies (7 years for all Teams).

Policy2 applies (5 years for Team1).

Conflict rule: For retention, the longest duration wins.

Therefore, the message stays 7 years, not 5.

✅ Answer: NO

???? Statement 2: User1 can see the message sent by User2 for up to seven years.

Location = Private 1:1 chat (User2 → User1).

For User1’s mailbox: Policy1 applies (7 years).

For User2’s mailbox: Policy2 applies (5 years).

Retention in Teams chats is per-user, so each participant may have different durations.

For User1, the retention is 7 years.

✅ Answer: YES

???? Statement 3: The message deleted by User1 will be moved to the SubstrateHolds folder.

Location = Team2 channel.

User1 deletes the message, but retention policy (Policy1) applies (7 years).

Retention overrides user deletion: message is moved to the SubstrateHolds folder in the hidden mailbox for preservation.

???? Reference: How retention works with SubstrateHolds

✅ Answer: YES

User1 can delete File1 on March 10, 2023.

No - File1 has Retention1 applied, which retains it for 4 years with a " Retain only " action. This means it cannot be deleted during the retention period, which ends on March 1, 2027.

User2 can delete File1 on March 10, 2027.

No - User2 is a Member and does not have the Owner role, which is required to delete files under retention policies during the retention period. Additionally, the " Retain only " action prevents deletion until the retention period ends on March 1, 2027.

User2 can edit File2 on March 15, 2025.

No - File2 has Retention2 applied, which retains it for 2 years with a " Retain and delete " action. This means the file is protected from edits or deletions during the retention period, which ends on March 1, 2025. Since March 15, 2025, is after the retention period, the file would be eligible for deletion, but the question specifies editing, which is restricted during the retention period.

Policy tips in DLP: Policy tips are messages shown to users when their action (such as sending sensitive content via email) conflicts with a DLP policy.

For Exchange email location, policy tips are supported in the following apps:

Outlook for Microsoft 365 (desktop client) ✅

Outlook on the web (OWA) ✅

Outlook Mobile (iOS/Android) ❌ Policy tips are not shown in mobile apps. Instead, DLP actions (block/restrict/send incident report) still apply, but the user does not see a policy tip notification.

Therefore:

Supported: Outlook for Microsoft 365, Outlook on the web.

Not supported: Outlook Mobile apps.

Since you need to automatically apply a sensitivity label to resumes based on their content and structure (work experience, education, accomplishments), a trainable classifier is the best choice.

Trainable classifiers use machine learning to identify unstructured data, such as resumes, contracts, or legal documents. Instead of relying on predefined patterns (like keywords or regular expressions), a trainable classifier learns from sample documents and can accurately identify resumes even if they are formatted differently.

Final Approach:

● Train a trainable classifier using sample resumes.

● Deploy the classifier in Microsoft Purview.

● Configure a sensitivity label to be automatically applied when a document matches the classifier.

Box 1: Publishing a Sensitivity Label

Sensitivity labels can be published to Microsoft 365 groups, security groups, SharePoint Online sites, and Microsoft Teams. Since we have:

● Group1 (Microsoft 365 group) - Supported

● Group2 (Security group) - Supported

● Site1 (SharePoint Online site) - Supported

● Team1 (Microsoft Teams team) - Supported

This means we can publish Label1 to Group1, Group2, Site1, and Team1.

Box 2: Auto-Applying a Sensitivity Label

Auto-apply policies for sensitivity labels work on:

● SharePoint Online sites (documents)

● OneDrive (documents)

● Exchange email (messages)

However, labels cannot be auto-applied to Microsoft 365 groups or Teams directly because labels are applied to files and emails, not to groups or Teams as entities. Since Site1 (a SharePoint Online site) supports auto-apply, it is the correct option.

To review a Microsoft 365 Copilot usage report, you need to use Data Security Posture Management for AI (DSPM for AI) in the Microsoft Purview portal. DSPM for AI provides insights into AI-related activities, including Copilot usage, risk assessments, and data security posture related to AI interactions within Microsoft 365.

Trainable classifiers in Microsoft Purview require a source of documents that can be labeled as examples of what the classifier should recognize. Supported sources include SharePoint Online and Exchange Online mailboxes. On-premises SharePoint Server sites, Azure File shares, and NFS file shares are not supported for classifier training.

Let’s break it down:

File1.docx → DLP action = None

No DLP restrictions, so it is fully accessible to both User1 (owner) and User2 (member).

File2.docx → DLP action = Matched by DLP

“Matched” means the DLP policy detected sensitive content but has not blocked access. Instead, it may generate an alert or policy tip.

Both User1 and User2 can still open this file.

File3.docx → DLP action = Blocked by DLP

“Blocked” means the DLP policy actively restricts access or sharing of the file.

User2 (member) cannot open this file.

However, User1 (site owner) can open it because site collection admins and owners always retain full control over content, even if a DLP rule applies.

Ref: Microsoft Purview DLP policy tips and enforcement

→ DLP policies do not prevent SharePoint/OneDrive site collection admins (owners) from accessing content.

✅ Final Answer Table:

User1 (Site Owner): File1.docx, File2.docx, File3.docx

User2 (Site Member): File1.docx, File2.docx