A program or set of programs which hides itself by subverting or evading the computer's security mechanisms, then allows remote users to secretly control the computer's operating system.
Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.
More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more information.
Rootkit:W32/Agent.UI creates a device named "\Device\IWEUFHKSEF" and sets up symbolic link named "\??\IWEUFHKSEF" to accept control codes from usermode programs.
It removes all hooked addresses corresponding to all NTFuntions (which are implemented in Ntoskrnl.exe), then restores them to their original values.
See the Hupigon.OGA description for additional details.