Account Security Problems

How to Check Microsoft 365 Devices for a Virus

Maira Mehtab Oct 10, 2026 869 views

Question details

The user suspects their computer is infected with malware and needs to run a security scan to protect their Microsoft 365 accounts.

How to Check Microsoft 365 Devices for a Virus

Product: Microsoft 365
Device & OS: Windows
Scenario: Suspecting a malware infection on a device used to access Microsoft 365, requiring a thorough virus scan before continuing to use sensitive accounts.
Observed behavior: Need to securely scan the system to detect and remove potential malware threats to prevent account compromise.

Before you start

Ensure you save any open documents and close your Microsoft 365 applications before proceeding, as an offline security scan will automatically restart your device.

Solution 1Recommended

Run a Security Scan Using Windows Security

Use the built-in Windows Security tool to perform a Full scan or a Microsoft Defender Antivirus Offline scan to detect and remove malware.

Windows includes a comprehensive security tool that can scan for viruses and threats. If you suspect your Microsoft 365 device is compromised, running a deep scan is highly recommended to secure your login credentials and files.

Open Windows Security

Click the Start menu, type 'Windows Security' in the search bar, and select the application from the search results.

Access Virus & threat protection

In the Windows Security dashboard, click on 'Virus & threat protection' located on the left-hand navigation pane.

Open Scan options

Under the 'Current threats' section, click on the 'Scan options' link to view advanced scanning methods.

Run a Full or Offline Scan

Select either 'Full scan' for a comprehensive check of all files, or 'Microsoft Defender Antivirus (offline scan)' for persistent malware. Click the 'Scan now' button to begin.

Review and Remove Threats

Once the scan is complete, review the results provided by Windows Security and follow the on-screen prompts to quarantine or remove any detected threats.

Run a Security Scan Using Windows Security

Offline Scan Requirement: The Microsoft Defender Antivirus Offline scan will restart your PC and takes about 15 minutes to complete. Make sure all your work is saved before starting.

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1. Download the Installer: Visit the official WPS Office website and click the free download button for your operating system.
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Frequently Asked Questions

Can a computer virus steal my Microsoft 365 login credentials?

Yes, certain types of malware, such as spyware and keyloggers, are designed to capture your keystrokes and steal sensitive information like your Microsoft 365 passwords and account details.

What is the difference between a Full scan and a Microsoft Defender Offline scan?

A Full scan checks all files and running programs while Windows is active. An Offline scan restarts your PC to detect and remove highly persistent malware that might try to bypass detection while the operating system is running.

Do I need a third-party antivirus if I already use Microsoft 365 on Windows?

Windows Security provides robust, built-in protection that is sufficient for most users. However, you can use reputable third-party antivirus software if you require advanced security features for highly sensitive business data.

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