Hello White,
The services with the "_81fff" suffix, such as SyncHost_81fff, Udk User Service_81fff, and UserDataSvc_81fff, are legitimate Windows services. These are known as per-user services. When a user signs in to Windows, the operating system creates these services specifically for that user session. The hexadecimal number at the end of the service name, like "_81fff," is unique to each user session and will change every time you log in
So, there's no need to worry—these services are part of the normal operation of Windows.
If you have any other questions or concerns, feel free to ask!
Regards
Levi