If an old device works, it is not necessarily safe
Sometimes it can seem that any (even old) device that is functional is suitable for the job. However, this assumption is often wrong.
Did you receive an email with an attachment you weren't expecting? You can give an attacker access to your entire computer and all your data with a single click. Therefore, make sure that you have received the email legitimately from a specific individual related to you; until then, do not click on any attachments in the email.
This is the result of a new vulnerability in Windows for which there is, unfortunately, no patch yet. A fix is being actively worked on, but until it is ready, only our sanity can protect us.
As soon as we know more details, we will update you.