Esegui 
Se lo elimino (o con Virit o con HiJackthis o manualmente) all'avvio successivo ricompare sotto altro nome ma con la stessa icona (che allego)
Vi allego anche il log di Hijackthis :
Logfile of HijackThis v1.97.7
Scan saved at 14.29.17, on 17/02/2007
Platform: Windows ME (Win9x 4.90.3000)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)
Running processes:
C:\WINDOWS\SYSTEM\KERNEL32.DLL
C:\WINDOWS\SYSTEM\MSGSRV32.EXE
C:\WINDOWS\SYSTEM\mmtask.tsk
C:\WINDOWS\SYSTEM\MPREXE.EXE
C:\WINDOWS\SYSTEM\STIMON.EXE
C:\WINDOWS\SYSTEM\KB891711\KB891711.EXE
C:\WINDOWS\SYSTEM\KB918547\KB918547.EXE
C:\WINDOWS\SYSTEM\MSTASK.EXE
C:\WINDOWS\EXPLORER.EXE
C:\WINDOWS\SYSTEM\SRVZFKVO.EXE
C:\WINDOWS\SYSTEM\RNAAPP.EXE
C:\WINDOWS\SYSTEM\TAPISRV.EXE
C:\WINDOWS\TASKMON.EXE
C:\WINDOWS\SYSTEM\SYSTRAY.EXE
C:\PROGRAMMI\WINAMP\WINAMPA.EXE
C:\WINDOWS\SYSTEM\GSICON.EXE
C:\WINDOWS\SYSTEM\DSLAGENT.EXE
C:\WINDOWS\MIXER.EXE
C:\WINDOWS\SYSTEM\WMIEXE.EXE
C:\WINDOWS\TEMP\GZILYA.EXE
C:\WINDOWS\SYSTEM\RESTORE\STMGR.EXE
C:\WINDOWS\SYSTEM\DDHELP.EXE
C:\WINDOWS\SYSTEM\WBEM\WINMGMT.EXE
C:\PROGRAMMI\BITTORNADO\BTDOWNLOADGUI.EXE
C:\PROGRAMMI\BITTORNADO\BTDOWNLOADGUI.EXE
C:\PROGRAMMI\EMULE\EMULE.EXE
C:\PROGRAMMI\INTERNET EXPLORER\IEXPLORE.EXE
C:\PROGRAMMI\INTERNET EXPLORER\IEXPLORE.EXE
C:\WINDOWS\SYSTEM\PSTORES.EXE
C:\PROGRAMMI\WINZIP\WINZIP32.EXE
C:\WINDOWS\TEMP\WZ204F\HIJACKTHIS.EXE
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://arianna.libero.it
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.libero.it/
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyServer = proxy.libero.it:8080
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = abbonati.libero.it;www.libero.it;*.libero.;*.;;<local>
O1 - Hosts: 205.238.40.52 www.winmx.com err.winmx.com
O1 - Hosts: 205.238.40.1 cache0.winmx.com test3201.winmx.com test3205.winmx.com
O1 - Hosts: 205.238.40.2 cache1.winmx.com test3202.winmx.com test3206.winmx.com
O1 - Hosts: 82.43.224.20 cache2.winmx.com test3203.winmx.com test3207.winmx.com
O1 - Hosts: 82.204.21.111 cache3.winmx.com test3204.winmx.com test3208.winmx.com
O1 - Hosts: 205.238.40.1 c3310.z1301.winmx.com c3310.z1302.winmx.com c3310.z1303.winmx.com c3310.z1304.winmx.com c3310.z1305.winmx.com c3310.z1306.winmx.com
O1 - Hosts: 205.238.40.1 c3311.z1301.winmx.com c3311.z1302.winmx.com c3311.z1303.winmx.com c3311.z1304.winmx.com c3311.z1305.winmx.com c3311.z1306.winmx.com
O1 - Hosts: 205.238.40.1 c3312.z1301.winmx.com c3312.z1302.winmx.com c3312.z1303.winmx.com c3312.z1304.winmx.com c3312.z1305.winmx.com c3312.z1306.winmx.com
O1 - Hosts: 205.238.40.2 c3313.z1301.winmx.com c3313.z1302.winmx.com c3313.z1303.winmx.com c3313.z1304.winmx.com c3313.z1305.winmx.com c3313.z1306.winmx.com
O1 - Hosts: 205.238.40.2 c3314.z1301.winmx.com c3314.z1302.winmx.com c3314.z1303.winmx.com c3314.z1304.winmx.com c3314.z1305.winmx.com c3314.z1306.winmx.com
O1 - Hosts: 205.238.40.2 c3315.z1301.winmx.com c3315.z1302.winmx.com c3315.z1303.winmx.com c3315.z1304.winmx.com c3315.z1305.winmx.com c3315.z1306.winmx.com
O1 - Hosts: 82.43.224.20 c3316.z1301.winmx.com c3316.z1302.winmx.com c3316.z1303.winmx.com c3316.z1304.winmx.com c3316.z1305.winmx.com c3316.z1306.winmx.com
O1 - Hosts: 82.43.224.20 c3317.z1301.winmx.com c3317.z1302.winmx.com c3317.z1303.winmx.com c3317.z1304.winmx.com c3317.z1305.winmx.com c3317.z1306.winmx.com
O1 - Hosts: 82.204.21.111 c3318.z1301.winmx.com c3318.z1302.winmx.com c3318.z1303.winmx.com c3318.z1304.winmx.com c3318.z1305.winmx.com c3318.z1306.winmx.com
O1 - Hosts: 82.204.21.111 c3319.z1301.winmx.com c3319.z1302.winmx.com c3319.z1303.winmx.com c3319.z1304.winmx.com c3319.z1305.winmx.com c3319.z1306.winmx.com
O1 - Hosts: 205.238.40.1 c3520.z1301.winmx.com c3520.z1302.winmx.com c3520.z1303.winmx.com c3520.z1304.winmx.com c3520.z1305.winmx.com c3520.z1306.winmx.com
O1 - Hosts: 205.238.40.1 c3521.z1301.winmx.com c3521.z1302.winmx.com c3521.z1303.winmx.com c3521.z1304.winmx.com c3521.z1305.winmx.com c3521.z1306.winmx.com
O1 - Hosts: 205.238.40.1 c3522.z1301.winmx.com c3522.z1302.winmx.com c3522.z1303.winmx.com c3522.z1304.winmx.com c3522.z1305.winmx.com c3522.z1306.winmx.com
O1 - Hosts: 205.238.40.2 c3523.z1301.winmx.com c3523.z1302.winmx.com c3523.z1303.winmx.com c3523.z1304.winmx.com c3523.z1305.winmx.com c3523.z1306.winmx.com
O1 - Hosts: 205.238.40.2 c3524.z1301.winmx.com c3524.z1302.winmx.com c3524.z1303.winmx.com c3524.z1304.winmx.com c3524.z1305.winmx.com c3524.z1306.winmx.com
O1 - Hosts: 205.238.40.2 c3525.z1301.winmx.com c3525.z1302.winmx.com c3525.z1303.winmx.com c3525.z1304.winmx.com c3525.z1305.winmx.com c3525.z1306.winmx.com
O1 - Hosts: 82.43.224.20 c3526.z1301.winmx.com c3526.z1302.winmx.com c3526.z1303.winmx.com c3526.z1304.winmx.com c3526.z1305.winmx.com c3526.z1306.winmx.com
O1 - Hosts: 82.43.224.20 c3527.z1301.winmx.com c3527.z1302.winmx.com c3527.z1303.winmx.com c3527.z1304.winmx.com c3527.z1305.winmx.com c3527.z1306.winmx.com
O1 - Hosts: 82.204.21.111 c3528.z1301.winmx.com c3528.z1302.winmx.com c3528.z1303.winmx.com c3528.z1304.winmx.com c3528.z1305.winmx.com c3528.z1306.winmx.com
O1 - Hosts: 82.204.21.111 c3529.z1301.winmx.com c3529.z1302.winmx.com c3529.z1303.winmx.com c3529.z1304.winmx.com c3529.z1305.winmx.com c3529.z1306.winmx.com
O4 - HKLM\..\Run: [TaskMonitor] C:\WINDOWS\taskmon.exe
O4 - HKLM\..\Run: [SystemTray] SysTray.Exe
O4 - HKLM\..\Run: [TotalRecorderScheduler] "C:\Programmi\HighCriteria\TotalRecorder\TotRecSched.exe"
O4 - HKLM\..\Run: [HDAudio Driver 1.0] C:\WINAMP.EXE
O4 - HKLM\..\Run: [WinampAgent] C:\Programmi\Winamp\winampa.exe
O4 - HKLM\..\Run: [PCHealth] C:\WINDOWS\PCHealth\Support\PCHSchd.exe -s
O4 - HKLM\..\Run: [GSICONEXE] GSICON.EXE
O4 - HKLM\..\Run: [DSLAGENTEXE] dslagent.exe USB
O4 - HKLM\..\Run: [C-Media Mixer] Mixer.exe /startup
O4 - HKLM\..\Run: [ScanRegistry] C:\WINDOWS\scanregw.exe /autorun
O4 - HKLM\..\Run: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKLM\..\Run: [QuickTime Task] "C:\WINDOWS\SYSTEM\QTTASK.EXE" -atboottime
O4 - HKLM\..\Run: [GZILYA.EXE] C:\WINDOWS\TEMP\GZILYA.EXE
O4 - HKLM\..\RunServices: [StillImageMonitor] C:\WINDOWS\SYSTEM\STIMON.EXE
O4 - HKLM\..\RunServices: [KB891711] C:\WINDOWS\SYSTEM\KB891711\KB891711.EXE
O4 - HKLM\..\RunServices: [KB918547] C:\WINDOWS\SYSTEM\KB918547\KB918547.EXE
O4 - HKLM\..\RunServices: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKLM\..\RunServices: [SchedulingAgent] mstask.exe
O4 - HKLM\..\RunServices: [*StateMgr] C:\WINDOWS\System\Restore\StateMgr.exe
O4 - Startup: Microsoft Office.lnk = C:\Programmi\Microsoft Office\Office\OSA9.EXE
O9 - Extra 'Tools' menuitem: Sun Java Console (HKLM)
O9 - Extra button: Related (HKLM)
O9 - Extra 'Tools' menuitem: Show &Related Links (HKLM)
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 (HKLM)
O12 - Plugin for .pdf: C:\PROGRA~1\INTERN~1\PLUGINS\nppdf32.dll
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://download.macromedia.com/pub/shoc ... wflash.cab
O16 - DPF: {4F1E5B1A-2A80-42CA-8532-2D05CB959537} - http://by116fd.bay116.hotmail.msn.com/r ... nPUpld.cab
O16 - DPF: {9F1C11AA-197B-4942-BA54-47A8489BB47F} - http://v4.windowsupdate.microsoft.com/C ... 023.126875
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {4C39376E-FA9D-4349-BACC-D305C1750EF3} - http://tools.ebayimg.com/eps/wl/activex ... 0-3-48.cab
O16 - DPF: {FE0BD779-44EE-4A4B-AA2E-743C63F2E5E6} - http://pdl.stream.aol.com/downloads/aol ... _en_dl.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} - http://acs.pandasoftware.com/activescan ... asinst.cab
O16 - DPF: {56336BCB-3D8A-11D6-A00B-0050DA18DE71} (RdxIE Class) - http://software-dl.real.com/15f1fa68cc6 ... xIE601.cab
Ecco ,io non capisco cosa siano questi:
C:\WINDOWS\SYSTEM\SRVZFKVO.EXE
C:\WINDOWS\SYSTEM\RNAAPP.EXE
oltre a questo :
O4 - HKLM\..\Run: [GZILYA.EXE] C:\WINDOWS\TEMP\GZILYA.EXE
