marioforever.exe is also known as W32.Mariofev.A and you can remove it as follows :

1. Temporarily Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Reboot computer in SafeMode
4. Run a full system scan and clean/delete all infected file(s)
5. Find and stop the service.
Click Start > Run.
- Type services.msc, and then click OK.
- Locate and select the service that was detected.

Service name: SCNa
Display name: SCNa Service

- Click Action > Properties.
- Click Stop.
- Change Startup Type to Manual.
- Click OK and close the Services window.

6. Delete/Modify any values added to the registry. [how to edit registry]
Navigate to and delete the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\[NUMBER]\”[34 DIGIT HEX NUMBER]” = “[RANDOM DATA]”
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
\”ztpInit_Dlls” = “nvrsma”
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\”ccnt” = “[NUMBER OF INFECTION ATTEMPTS]”
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\”mid” = “[RANDOM HEX DATA]”

Navigate to and delete the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\SCNa

7. Exit registry editor and restart the computer.