Unknown folder suddenly appearing in "move to folder" picklist. Is there a security breach? (see image)

I'm seeing the same issue with one of my users:

I also have this problem.

This is NOT Thai, I believe it is Korean looking at the characters. I am unable to locate it or copy it in order to translate it, or to search for it.

I ran Windows Defender offline scan.

Now the folder still visible, but when I try to move something there it says it is not available.

It does seem to be malicious based on this behavior.

I'm seeing the same thing. Currently running Outlook 365 insider channel (Version 2403 Build 17425.20146).

Hello,

It seems you're experiencing a peculiar issue with an unknown folder appearing in your "move to folder" picklist in Outlook on Windows, which doesn't occur in the web version or on the iPhone/iPad apps. There are a few steps and considerations to address this:

Folder Visibility:

The folder might be hidden in your folder list. Check your list of folders carefully, including any collapsed sections, to see if the folder is there but not immediately visible. Outlook Configuration:

This could be an issue with your Outlook configuration on Windows. Try resetting the view settings in Outlook: Go to the View tab, click on 'Change View', and then select 'Reset View'. This can help if the issue is due to a corrupted view setting. Create a New Outlook Profile:

Sometimes creating a new profile can resolve odd issues like this. Go to Control Panel > Mail > Show Profiles. Click on 'Add' to create a new profile, configure your email account, and see if the problem persists. Scan for Malware:

Even though you've run a McAfee scan, it's still a good idea to use a different malware scanning tool as well. Different tools can pick up different issues. Consider running a scan with another reputable antivirus or anti-malware program. Check for Rules and Scripts:

Check if there are any rules set up in Outlook that might be creating this folder. Go to File > Manage Rules & Alerts and review your rules. Also, ensure there are no scripts or add-ins running in Outlook that might create such a folder. Contact IT Support or Microsoft:

If your laptop is managed by an IT department, report this issue to them as it might be related to enterprise policies or network issues. Otherwise, consider reaching out to Microsoft Support for more specialized assistance. System Restore:

If you noticed this issue started occurring after a specific update or change in your system, you could consider using System Restore to revert your computer to a state before the issue began. This should be a last resort, as it can affect other software and updates.

The screenshot you've shared shows the 'move to folder' picklist in Outlook with a folder named in Thai, which you mentioned translates to "The book will be released soon..." and does not exist elsewhere in your Outlook folders.

Here are some additional steps to consider:

Hidden Folders: Check for hidden folders within Outlook. You can do this by right-clicking on any folder and selecting Properties, then checking if there's an option that might be hiding the folder in question.

Investigate Folder Source: Look into the source of the email account tied to this folder. If it’s a Gmail account, for example, check the Gmail interface to see if the folder exists there. Sometimes, folders created on the email server can sync in unexpected ways with the Outlook client.

Search for the Folder: Use Outlook's search function to search for the folder by its name. This might help locate it if it's hidden or nested within another folder.

Outlook Add-Ins: Check if there are any add-ins installed that might have created the folder. Go to File > Options > Add-Ins and manage or disable add-ins to see if the folder disappears.

Outlook Support: As this folder appears in only one version of Outlook and not others, it suggests a client-specific issue. You could reach out to Microsoft Support with this screenshot as it could be a bug or a specific issue with your installation of Outlook.

Check for Compromise: Although you've run a McAfee scan, there could be a security breach that your antivirus has not detected. You might want to change your email account password and enable two-factor authentication as precautionary measures. Also, review any recent login activity for any signs of unauthorized access.

Reinstall Outlook: If no solution works, consider backing up your emails and settings, uninstalling Outlook, and then reinstalling it. This could clear up any corrupt data causing the mysterious folder to appear.

Since this issue is specific to your Outlook installation on Windows, it's a good idea to back up your data before making any major changes. If the problem persists, seeking direct support from Microsoft or a professional IT technician would be advisable.

This is what appears when click "move to folder". Thanks.