Data Protection Issues

How to Fix Trojan Warning Returning in OneDrive Temp Folder

Maira Mehtab Sep 20, 2026 869 views

Question details

The user experiences a recurring Trojan warning from Vipre antivirus in the local C:\OneDriveTemp folder that reappears whenever OneDrive resynchronizes.

Product: Microsoft OneDrive
Device & OS: Windows
Scenario: Syncing files using OneDrive while a third-party antivirus is actively scanning the local drive.
Observed behavior: A Trojan warning is triggered in the C:\OneDriveTemp folder. Deleting the file and pausing sync removes the threat temporarily, but it returns upon resyncing. The flagged file is not visible on the OneDrive web version.

Before you start

Temporarily pause your OneDrive synchronization to prevent the suspicious file from repeatedly downloading while you investigate the flagged threat.

Solution 1Recommended

Scan and Verify with Microsoft Defender

Use Microsoft Defender to get a second opinion on the detected file, as third-party antivirus alerts can sometimes be false positives.

Because temporary synchronization files are often encrypted or fragmented, some third-party antivirus programs may incorrectly identify them as Trojans. Running a scan with built-in Windows security tools can help determine if the threat is genuine.

Pause OneDrive Sync

Click the OneDrive cloud icon in your system tray, click the Gear (Help & Settings) icon, and select 'Pause syncing'.

Open Windows Security

Click the Start menu, type 'Windows Security', and press Enter to launch the built-in antivirus dashboard.

Run a Custom Scan

Navigate to 'Virus & threat protection', click 'Scan options', select 'Custom scan', and then click 'Scan now'. Select the C:\OneDriveTemp folder to check for genuine threats.

False Positives: If Microsoft Defender does not flag the folder, the Vipre warning is likely a false positive caused by the way OneDrive handles temp files.

Solution 2

Quarantine the File and Contact Antivirus Support

If the file is consistently flagged by your specific antivirus software, quarantine it and reach out to their support team for signature analysis.

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Frequently Asked Questions

Why does the Trojan warning only appear in the OneDriveTemp folder?

The OneDriveTemp folder is used to temporarily store data chunks during synchronization. Some third-party antivirus programs mistakenly flag these incomplete or fragmented files as malicious, triggering a localized warning.

Why isn't the detected file visible on the OneDrive website?

The file in the Temp folder is likely an incomplete data fragment or a hidden system cache file generated during the local sync process. Because it hasn't been fully assembled or uploaded, it will not appear as a standard document on the cloud server.

Can I safely delete the contents of the OneDriveTemp folder?

Yes, you can safely delete the contents of this folder after pausing your OneDrive synchronization. Once the folder is cleared, you can resume syncing, and OneDrive will recreate the necessary temporary files properly.

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