Remote Desktop Security Warning

If you are using Remote Desktop to access work systems, you may see a warning message stating that the remote connection is “unknown” or that the identity of the remote computer can’t be verified. While this message can look concerning at first glance, it is often a normal part of connecting to internal business systems — and it plays an important role in keeping your data secure.

This warning appears when Windows cannot fully confirm the security certificate used by the remote computer. This has always been the case but previously you have been able to bypass that message. The purpose of the message is not to block your work, but to encourage you to pause and confirm that the connection is legitimate. The most recent update Security Update from Microsoft (click here to read the general update, and here for the RDP specific updates) stops the ability to bypass this.

What does this warning look like?

The message typically includes wording such as “Unknown remote connection” or “We could not verify the identity of the remote computer.” It may also display the address of the system you are connecting to and present options such as allowing clipboard or printer access. This is a safety feature designed to prevent accidental connections to untrusted systems.

When is it safe to continue?

You should only proceed if you were expecting to connect to the system, you recognise the destination, such as a company server or system you regularly use, you are connecting using your usual work setup, such as via a company VPN or approved remote access process

In these cases, the connection is usually legitimate, and the warning is simply informational.

When should you stop?

If the connection attempt is unexpected, unfamiliar, or you’re unsure why the message appeared, you should cancel the connection and contact us by for advice. Accepting a connection you don’t recognise could expose your login details or sensitive business data.

What will be done to remedy this message?

Historically we haven’t really had the need to provide a matching certificate for these connections. To alleviate and ensure you are not prompted, we will be deploying a matching certificate which will stop the majority of those messages when you are connecting to your Remote Desktop Servers, ensuring you don’t get those prompts and can continue to work securely.

Our security recommendation

Security warnings like this exist to protect you. Currently, if you are using the same connection you are always using, it should be safe to continue through and connect to the work environment. This can be done by clicking on the “I understand and allow RDP to open this device for my account”, and then Connecting to the server. When in doubt, it’s always better to stop and check than to click through. If you ever have questions about a security prompt or aren’t sure whether a connection is safe, please contact our support team — we’re here to help.