Hi , Miles.
I am Ivan, I will help you with this.
Un_a.exe is a known component of ByteFence, Dashlane and TeamViewer security.
As it can also be an uninstallation file of Mozilla firefox Defense but as the file is in Temporary you can clean it using Disk cleanup.
https://support.microsoft.com/en-us/windows/dis...
Independent Advisor - Community
Thanks