Issue

While backing up a SharePoint site, the job will have been completed successfully but your Cirrus logs say that it Failed to back up item, Item may have a virus reported by the virus scanner plug-in. 

Summary

When checking your Cirrus backup session logs you may see the following warning. 

Warning

Processing site <Name> (<SharePoint Address>) finished with warning: Failed to backup item: <Item that could not be backed up>, Item may have a virus reported by the virus scanner plug-in.

Cause

Microsoft has its own inbuilt virus scanner for files that are uploaded to SharePoint, OneDrive and Teams. Microsoft has determined that the file in question contains a virus. For more information on the virus scanner please see this Microsoft Article. 

For further information please see this Veeam Article.

Resolution

It is recommended that you have the user or the users Microsoft 365 Admin delete the file.  You can also have the file unblocked by an Administrator in your Microsoft 365 tenancy if you believe this is a false positive. Please take precautions and only unblock the file if you are 100% certain it contains no viruses. 

If you want to delete or unblock the file please see: What to do when a malicious file is found.

Cirrus will be unable to back up this file until it is unblocked by your Microsoft 365 Admin.

References

If you are unsure of how to check your backup session logs, please see the following: View Backup Logs.

Help & Support

If you have followed the steps outlined above and the issue recurs in the next backup cycle, or you need help performing these changes, you can access online help at https://support.cirrusbackup.com.